Circuit Note
CN-0352
Devices Connected/Referenced
Circuits from the Lab® reference designs are engineered and
tested for quick and easy system integration to help solve today’s
analog, mixed-signal, and RF design challenges. For more
information and/or support, visit www.analog.com/CN0352.
ADP5065
Fast Charge Battery Manager with Power Path
and USB Compatibility
ADG715
CMOS, Low Voltage Serially Controlled,
Octal SPST Switch
AD8601
Precision CMOS, Single-Supply, Rail-to-Rail,
Input/Output Wideband Operational Amplifier
AD8237
Micropower, Zero Drift, True Rail-to-Rail
Instrumentation Amplifier
AD8275
G = 0.2, Level Translation,16-Bit ADC Driver
AD8276
Low Power, Wide Supply Range, Low Cost,
Unity-Gain Difference Amplifier
ADuCM360
Low Power, Precision Analog Microcontroller
with Dual Sigma-Delta ADCs, ARM Cortex-M3
Cost Effective, Multichannel Lithium Ion Battery Testing System
EVALUATION AND DESIGN SUPPORT
Circuit Evaluation Boards
CN-0352 Evaluation System (EVAL-CN0352-EB1Z)
Evaluation system includes
EVAL-CN0352-EB1Z_IO (Input/Output Board, 8 Each)
EVAL-CN0352-EB1Z_MCU (MCU Board, 1 Each)
EVAL-CN0352-EB1Z_BAS (Base Board, 1 Each)
Design and Integration Files
Schematics, Source Code, Layout Files, Bill of Materials
CIRCUIT FUNCTION AND BENEFITS
The test system shown in Figure 1 is an accurate, cost effective,
8-channel battery testing system for single-cell, lithium ion (Li-ion)
batteries with open circuit voltage (OCV) between 3.5 V and 4.4 V.
The demand for Lithium ion (Li-ion) batteries is high for use in
both low power and high power applications, such as laptop
computers, mobile phones, portable wireless terminals, as well
as hybrid electric vehicles/all-electric vehicles (HEV/EV). Li-ion
batteries therefore require accurate and reliable test systems.
The battery test system in Figure 1 is composed of multiple
input/output boards (EVAL-CN0352-EB1Z_IO) for handling
the charging and discharging process, an MCU board (EVALCN0352-EB1Z_MCU) for battery data acquisition, testing,
monitoring, and temperature management, and a backplane
base board (EVAL-CN0352-EB1Z_BAS) that provides the
signal interconnections between the MCU board and the
multiple input/output boards.
The circuit uses the ADP5065 fast charging battery manager for
flexible, efficient, high stability charging control with low cost,
small printed circuit board (PCB) area, and ease of use
compared to traditional discrete solutions.
Highly integrated precision data acquisition and processing is
provided by the ADuCM360 precision analog microcontroller.
The ADuCM360 acquires the battery voltage, current, and
temperature. A high precision analog-to-digital converter
(ADC), digital-to-analog converter (DAC), and an on-chip
microcontroller allows completely self-contained control of the
charging and discharging process.
The analog front end is fully differential with high CMRR and
excellent immunity to both common-mode and ground noise
caused by large currents generated during the charge and
discharge cycles.
The number of channels can easily be expanded to further
reduce testing time and cost per battery.
Rev. A
Circuits from the Lab® reference designs from Analog Devices have been designed and built by Analog
Devices engineers. Standard engineering practices have been employed in the design and
construction of each circuit, and their function and performance have been tested and verified in a lab
environment at room temperature. However, you are solely responsible for testing the circuit and
determining its suitability and applicability for your use and application. Accordingly, in no event shall
Analog Devices be liable for direct, indirect, special, incidental, consequential or punitive damages due
toanycausewhatsoeverconnectedtotheuseofanyCircuitsfromtheLabcircuits. (Continuedonlastpage)
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2016 Analog Devices, Inc. All rights reserved.
Circuit Note
12842-001
CN-0352
Figure 1. Cost Effective, Multichannel Li-ion Battery Testing System
TO BASE BOARD
CNP-12
CNP-11
CNP-10
CNP-9
U1
+5VPWR
+5VPWR
1.0µH
VOUT
SW1
SW2
2.2µF
4.7µF
SW
ADP5065
VIN1
C3
22µF
VIN2
CFILT
4.7µF
+3.3VD
CNP-4
CNP-8
3MHz
BUCK
PGND1
A 4-WIRE KEVIN CONNECTION IS
RECOMMENDED SHORT JP2 AND
JP3 FOR 2-WIRE CONNECTION
ISO_S1
10k
IIN_EXT
CNP-1
CNP-2
CNP-7
SDA
SCL SCL
NRST SDA
CHARGE
CONTROL
BLOCK
SCL
SDA
AGND
V+
100pF
THR
V_WEAK_SET
JP2
1kΩ
BAT_SNS
0.1µF
I+
22µF
ISO_B2
SYS_ON_OK
1µF
0.02Ω
1%
ISO_B1
+5VA
CNS-9
CNS-10
BATTERY
CONNECTOR
ISO_S2
TRK_EXT
t°
10kΩ
ERT-JZEG103JA
PGND2
V–
JP3
U2
D1
D2
D3
D4
D5
D6
D7
D8
S1
S2
S3
S4
S5
S6
S7
S8
CNS-7
CNS-5
CNS-3
CNS-1
CNS-2
CNS-4
CNS-6
CNS-8
+5VA
0.1µF
RESET
A0
VDD
A1
GND SERIAL
PORT
SCL
VSS
SDA
HSINK 1
1kΩ
I_SENSE+
ADG715
100pF
V_DAC
THR_N
IEXT
THR_P
V_SENSE–
V_SENSE+
I_SENSE–
I_SENSE+
100pF
AUX
CONNECTOR
1kΩ
V_SENSE–
1kΩ
IEXT
1kΩ
THR_P
100pF
t°
10kΩ
1kΩ
THR_N
10kΩ
SCL
SDA
E-LOAD CIRCUIT
V4330K
HEAT SINK
1kΩ
V_SENSE+
NRST
I–
1kΩ
I_SENSE–
1kΩ
V_DAC
1
1W
1
1W
1
1W
1
1W
10kΩ THERMISTOR
NEEDS TO FIT
TOGETHER WITH
THE BATTERY
UNDER TEST
+5VA AD8601
10Ω
10MΩ
0.1µF
U3
AGND
PGND
12842-002
2 × SIR464
FOR COOLING THE E-LOAD
CIRCUIT DURING
DISCHARGING PROCESS
Figure 2. EVAL-CN0352-EB1Z_IO, Li-ion Battery Charging and Discharging Controlling Circuit (Simplified Schematic: All Connections and Decoupling Not Shown)
Rev. A | Page 2 of 10
Circuit Note
CN-0352
CIRCUIT DESCRIPTION
The 8-channel battery testing system (EVAL-CN0352-EB1Z)
contains eight input/output boards (EVAL-CN0352-EB1Z_IO)
and one MCU board (EVAL-CN0352-EB1Z_MCU) that plug
into one base board (EVAL-CN0352-EB1Z_BAS). The circuit
shown in Figure 2 is the input/output board.
The sample-and-hold circuits shown in Figure 3 control the
discharging voltage on each channel. The ADuCM360 refreshes
the discharging voltages of the input/output board sequentially by
outputting the preconfigured discharging control voltage for each
channel and then turning on the corresponding ADG715 switch.
MCU BOARD
INPUT/OUTPUT BOARDS
CH1
Input/Output Board (EVAL-CN0352-EB1Z_IO) Description
Battery Charging Control Using the ADP5065
+
1kΩ
E-LOAD
10MΩ
BAT1
0.1µF
ADG715
The ADP5065 handles all the necessary charging control for
single cell Li-ion or lithium polymer batteries, including the
constant current (CC), constant voltage (CV), and trickle
charge (TC) modes. The TC mode allows testing a deeply
discharged battery and ensures safety. The ADP5065 uses a
dc-to-dc switching converter architecture for high efficiency
during the charging process, compared to more traditional
linear regulators.
ADuCM360
CH2
+
1kΩ
12-BIT
DAC
E-LOAD
10MΩ
BAT2
0.1µF
CH8
The ADP5065 integrates a number of significant features to
guarantee the high reliability including thermal management,
battery fault detection, and fault recovery.
The charging parameters of ADP5065, such as fast charging
current, charging termination current, and charging termination
voltage, are all programmable through an I2C interface. This
programmability allows the ADP5065 to operate with many
different types of Li-ion batteries as well as to operate as a
complete battery charging and test controller.
Battery Discharging Control and Electronic Load (E-Load)
Circuit
The electronic load (E-load) circuit within the dashed rectangular
block in Figure 2 provides a programmable constant-current
load that uses the AD8601 precision CMOS op amp, four 1 W,
1% power resistors, and two power SIR464 MOSFETs.
The E-load current is accurately controlled by the control voltage
on the noninverting input of AD8601. The control voltage
(V_DAC from MCU board) can range from 0 V to 1 V, which
produces a load current of 0 A to 2 A. The typical discharging
termination voltage for Li-ion battery is 3.0 V. The minimum
allowable output voltage required by this E-load is
2A×1Ω=2V
The power MOSFETs and the power resistors consume all the
energy from the battery during discharging process. The cooling
system implemented in this module is only for demonstration
purposes, and additional attention is required to guarantee
adequate cooling performance when the discharging current is
higher than 750 mA.
Because the on-resistance of MOSFETs have a positive
temperature coefficient, multiple devices of the same type can
be used in parallel and controlled by a single loop shown as the
E-circuit in Figure 2. This is a common way to extend the
power handling ability of power MOSFET circuits.
+
BAT8
12842-003
ADG715
Figure 3. Sample-and-Hold Circuit for Multichannel Discharging Current
Control Circuit
Only one input/output board has its ADG715 switch closed
at any given time. The 0.1 μF capacitor is charged by the DAC
through a 1 kΩ resistor during the sampling interval and
discharged through the 10 MΩ resistor the 1 kΩ to ground
during the holding interval. The bandwidths for charging and
discharging are approximately 1.6 kHz and 0.16 Hz, respectively.
The 10 MΩ resistor is required to discharge the voltage on the
0.1 μF capacitor and pull the discharging voltage close to ground
if there is no MCU board connected.
Assuming an N-channel system and a sampling and holding time
of TS and TH, respectively, the following condition must be met:
TH = TS (N − 1).
Therefore more channels require a longer holding time, and the
leakage current produces a larger droop voltage. For the CN-0352
system, N = 8, TS = 1 ms, and TH = 7 ms, and the droop voltage
is negligible.
Thermal Management
Most Li-ion batteries cannot be charged at temperatures lower
than 0°C or above 60°C. Fast charging and discharging can only
be performed from 10°C to 45°C.
In addition to safety issues, the performance of the Li-ion cell
can change dramatically with temperature. Therefore, the
temperature of the battery needs to be measured with proper
accuracy to ensure the repeatability of the test results and also
to guarantee safety.
Battery temperature is monitored using 10 kΩ thermistors
connected to the temperature connector blocks with a 2-wire
connection. The battery under test is usually located near the
board, therefore the thermistor lead resistance is negligible.
There is another 10 kΩ thermistor on the input/output board
connected to the THR pin of ADP5065 as shown in Figure 2.
Rev. A | Page 3 of 10
CN-0352
Circuit Note
resistance to carry the charging and discharging current. The
V+ and V− lines sense the voltage of battery and carry only a
small bias current. The charging and discharging current is
sensed by measuring the voltage across the 0.02 Ω, 1% current
sense resistor.
This thermistor is for monitoring the temperature near the
heat sink on the input/output board, because the temperature
can be relatively high during discharging. The thermistor
temperature information is sensed and stored in the ADP5065
Charger Status Register 2 and is monitored by the MCU board
through the I2C bus. There are two headers on the input/output
board for the external fan connections with configurable pulsewidth modulation (PWM) signals assigned. If the thermistor
temperature is less that 45°C, the PWM signal to the fans is set
at 50% duty cycle by the MCU. If the temperature is greater than
45°C the duty cycle is increased to 95%. If the temperature is
greater than 60°C the ADP5065 automatically stops the charging
process. The temperature thresholds can be fine tuned by placing
a fixed resistor in parallel or in series with the thermistor.
All the battery information is sensed differentially to increase
the robustness and reduce the common-mode error, which is
very important because of the large ground currents during
charging and discharging.
MCU Board (EVAL-CN0352-EB1Z_MCU) Description
Voltage Conditioning Circuit
The circuit shown in Figure 4 shows the signal conditioning
circuits for the voltage, current, and temperature channels. All
the signals from input/output boards are routed into the analog
input channels of ADuCM360 and digitized by the two, on-chip,
24-bit, Σ-Δ integrated ADCs.
Battery Connection and Sensing
The battery under test is connected to the input/output board
by a 4-wire Kelvin connection to eliminate errors caused by lead
resistance. The I+ and I− connecting wires must have low lead
AD8275
–IN
100pF
1kΩ
V_SENSE–
VBAT: 0V TO 5V
10kΩ SENSE
200Ω
40kΩ
–IN
20kΩ REF2
50kΩ
+IN
20kΩ REF1
100pF
40kΩ
R11 5.6kΩ
R12 5.6kΩ
C16
1nF
C17
100pF
D4
SDM40E20LS 1kΩ
R55
R18 5.6kΩ
VOUT 8
2 +IN
FB 7
3 –IN
REF 6
4 –VS
+VS 5
THR_NIN
+5VA
RF2 90.9kΩ
THR_OUT+
THRPIN
THRNIN
THR_OUT–
THR_OUT+
THR_OUT–
C39
1nF
V_OUT+
V_OUT–
R56 1kΩ
RF1
90.9kΩ
R21 5.6kΩ
RG1
10kΩ
R22 5.6kΩ
C45
1nF
THRNIN
I_OUT+
I_OUT–
VDAC
+I_OUT
C29
1nF
–I_OUT
C31
100pF
AVDD_REG
AVDD_REG
AVDD
IOVDD
AVDD_REG
AVDD
IOVDD
AIN6/IEXC
AIN7
AIN8
AIN10
AIN11
AIN3
AIN2
THRPIN
R105 1kΩ
–V_OUT
C36
100pF
OUT
RG2 10kΩ
I_EXT
C34
1nF
+V_OUT
C30
1nF
C32
100pF
1 BW
C40
100pF
THR_PIN
R20 5.6kΩ
40kΩ
REF
I_EXT
R17 5.6kΩ
I_EXT
U3
10.µF
C41
100pF
2.2kΩ 0.1%
25ppm
R19 5.6kΩ
U5
AD8237
C18
100pF
I_SENSE–
40kΩ
200Ω
SENSE
I_SENSE+
C37
100pF
AVDD_REG
1kΩ
V_SENSE+
+IN
OUT
U2
1nF
AD8276
AIN5
AIN4
U1
ADuCM360
DAC
AGND
EPAD
P0.6
P0.7
P0.4/
RX
TX
DIR
P1.2
P1.3/
FAN_PWM1
FAN_PWM2
P1.0
P1.3
FAN1_SPD
FAN2_SPD
P2.0
P2.1
SCL
SDA
P0.0
P0.1
P0.2
A0
A1
A2
P0.3
P0.5
I2C_EN
SW_RST
12842-004
50kΩ
Figure 4. EVAL-CN0352-EB1Z_MCU, Signal Conditioning, Data Acquisition by ADuCM360 (Simplified Schematic: All Connections and Decoupling Not Shown)
Rev. A | Page 4 of 10
Circuit Note
CN-0352
The charging termination voltage is generated by the ADP5065
and is adjustable from 3.5 V to 4.42 V for compatibility with
different types of Li-ion batteries. Discharge termination voltage
is usually set to 3.0 V. In special circumstances, the battery
maybe deeply discharged to a voltage much lower than 3.0 V.
The discharge termination voltage can be set from 0 V to 5 V,
and that range covers almost conditions for Li-ion battery cells.
Current Conditioning Circuit
The sensed battery voltage is processed by the AD8275 (G = 0.2
difference amplifier) and the AD8276 (unity-gain difference
amplifier). The two amplifiers are connected in a balanced circuit
to provide a differential output with an overall gain of 0.2 and
an output common-mode voltage of 1.8 V.
The AD8237 is a micropower, zero drift, rail-to-rail
instrumentation amplifier. A simplified block diagram is shown
in Figure 5. The AD8237 utilizes the indirect current feedback
architecture, and achieves true rail-to-rail capability. The
common-mode input voltage can be equal to or slightly beyond
the power supply rails.
The battery current is sensed on the input/output boards by a
0.02 Ω resistor placed in series with the high side of the battery.
Assuming that the maximum current during testing is 2 A, the
maximum differential voltage across the resistor is ±40 mV with
the common-mode voltage equal to the battery voltage that can
be higher than 4.2 V.
The two 1 kΩ resistors placed in series with the AD8275 inputs
shown in Figure 4 act as current limiting protection resistors.
The 200 Ω resistors compensate for the reduction in gain due to
the 1 kΩ series resistors and restore the gain of the circuit to 0.2.
The gain of the AD8237 circuit is set to 10.09 by the ratio of
RF1 to RG1 (G = 1 + RF1/RG1). The RF2 and RG2 resistors
cancel the error from the input bias current.
With the equations set as shown,
The ±40 mV current sensed signal is converted to ±400 mV
with a reference voltage of AVDD_REG = 1.8 V.
VOUT   VOUT   0 .2  (VSENSE   V SENSE  )

VOUT   VOUT   2  V AVDD _ REG
The amplified and level-shifted current sense signal drives the
AIN5 and AIN4 differential inputs of the ADuCM360 which is
configured for a bipolar input, gain = 2, buffer enabled, and
internal reference enabled. The differential voltage at the input
of the ADuCM360 internal ADC is ±800 mV. The absolute
voltage on the input pins are both 1.0 V to 2.6 V.
The final voltage of VOUT+ and VOUT− is
VOUT   V AVDD _ REG  0 . 1  (V SENSE   V SENSE  )

VOUT   V AVDD _ REG  0 . 1  (V SENSE   V SENSE  )
For a 0 V to 5 V battery voltage range, VOUT+ and VOUT− vary from
1.8 V to 2.3V and 2.3 V to 1.8 V, respectively. The differential
output voltage (VOUT+ − VOUT−) is 0 V to 1 V. These ranges are
compatible with the common-mode and differential input
voltage requirements of ADuCM360.
The current and voltage information is sampled simultaneously
using the two internal ADCs in ADuCM360.
Differential and common-mode RFI and noise filters are placed
in front of the AD8275, AD8237, and ADuCM360 accordingly.
The configuration of ADuCM360 for voltage acquisition is as
follows: differential input on AIN3 and AIN2, unipolar, unitygain with buffer disabled, and internal reference.
INTERNAL
IN-AMP
AD8237
+
VOUT
TIA
–
RFI
FILTER
+IN
–VS
+VS
–VS
+
ALS
RFI
FILTER
–IN
+VS
–
V
VCM = S
2
FB
TO gm2
+
gm1
–
–
I2
gm2
+
V
VCM = S
2
+
–VS
+VS
ALS
Rev. A | Page 5 of 10
FB
R1
+
RFI
FILTER
–VS
Figure 5. AD8237 Simplified Schematic
R2
–
RFI
FILTER
TO gm1
–
I1
–IN
REF
12842-005
I1 – I2
+VS
CN-0352
Circuit Note
Battery Temperature Conditioning Circuit
The battery temperature is measured with a 10 kΩ thermistor
placed near or inside the battery casing. The value of the
thermistor resistor is determined by measuring the voltage
across the thermistor when driven with a known current.
As shown in Figure 6, the integrated current source in the
ADuCM360 (I_EXT) drives the 10 kΩ thermistor through a
series network that includes a 2.2 kΩ precision current sense
resistor, a Schottky diode for reverse voltage protection, two
1 kΩ current limit resistors, and a 10 kΩ bias voltage generator
resistor.
The maximum voltage drop through the series connected
circuit is
VMAX = IEXT × (1 kΩ + 2.2 kΩ + 1 kΩ + 50 kΩ +10 kΩ) + VF
= IEXT × 64.2 kΩ + 0.31 V
The total voltage drop must be less than (AVDD − 0.85 V). The
exciting current is limited by
IEXT << (AVDD − 0.85 V − 0.31 V)/64.2 kΩ
Therefore, the maximum allowable exciting for this circuit is
33.3 μA. The exciting current is set to 10 μA so that the voltage
across the 10 kΩ resistor is less than 0.5 V. The internal
ADuCM360 PGA is set for a gain of 2, and the internal buffer of
ADuCM360 is enabled.
The bias voltage on the temperature input is 10 μA × 10 kΩ =
0.1 V in order to meet the common-mode input voltage
requirement of the ADuCM360 when the internal buffer is
enabled.
The excitation current reference channel and thermistor voltage
channels are sampled simultaneously to cancel any commonmode error sources, such as drift in the exciting current source
or the power supply.
The configuration for temperature acquisition for the reference
channel is: differential input, unipolar, gain = 32, buffer
enabled, and internal reference.
The configuration for thermistor channel is: differential input,
unipolar, gain = 2, buffer enabled. and internal reference.
EVAL-CN0352-EB1Z-MCU
100pF
THR_OUT+
1nF
THR_OUT–
REVERSE
PROTECTION
SDM40E20LS
5.6kΩ
5.6kΩ
0.1%
2.2kΩ
25ppm
ADG715
100pF
1nF
THR_PIN
1kΩ
1kΩ
100pF
1kΩ
THR_NIN
CURRENT
LIMITATION
1kΩ
2.5kΩ TO 50kΩ FOR
–10° TO +60°C
1kΩ
t°
1nF
10kΩ
0.1V V_BIAS GENERATED BY 10kΩ × 10µA FOR ADuCM360
Figure 6. Battery Temperature Conditioning Circuit
Rev. A | Page 6 of 10
12842-006
I_EXT
CURRENT
LIMITATION
1kΩ
EVAL-CN0352-EB1Z-IO
Circuit Note
CN-0352
Base Board (EVAL-CN0352-EB1Z_BAS) Description
I2C Interface Extension
3.3VD
1kΩ
SCL
SDA
3.3VD
1kΩ
3.3VD
VCC
Y0
Y1
Y2
74LVC138 Y3
Y4
E1
Y5
E2
Y6
E3
GND Y7
I2C_EN
DGND
SCL_CS1
SCL_CS2
SCL_CS3
SCL_CS4
SCL_CS5
SCL_CS6
SCL_CS7
SCL_CS8
SCL_CH1
0Ω
SDA_CH1
SCL_CH2
0Ω
SDA_CH2
SCL_CH8
0Ω
DGND
SDA_CH8
12842-007
A0
A1
A2
A0
A1
A2
Figure 7. I2C interface Extension Circuit
–0.95
–1.00
–1.05
12842-008
–1.10
2201
2001
1801
1601
1401
1201
1001
801
401
601
201
–1.15
1
The number of battery channels can be expanded by adding
additional EVAL-CN0352-EB1Z systems that share one RS485 bus
connection to the PC. In this situation, each module must have
a unique ID from 1 to 255. The ID0 is reserved. The CN-0352
evaluation software scans all the IDs and records the ID and
channel number for each available ID. Note that the baud rate
of RS485 bus is the limiting factor to channel expansion using
this approach.
–0.90
VOLTAGE (mV)
The base board provides the interconnections between the
input/output boards and MCU board. The user can address the
ADP5065 and the ADG715 on a particular input/output board
by using different I2C DEV_ID. The logic shown in Figure 7
uses the 3-bit general-purpose input/outputs (GPIOs) from the
ADuCM360 to route the SCLK signal to the proper
input/output board. More channels can be added; however,
more channels require higher ADC sampling rates, more MCU
ram size, faster refreshing rate for the discharging voltage, and
higher communication bandwidth to the upper-level processer.
SAMPLING INTERVAL
Figure 8. Voltage Noise Measured with Battery Connection Pins Shorted
(140 μV p-p Voltage Noise)
1.20
Circuit Performance Measurements
CURRENT (mA)
1.15
1.10
1.05
1.00
12842-009
System noise was measured by shorting the battery voltage
sense pins, V+ and V−, together on the battery connector
(shown in Figure 3) and measuring the peak-to-peak variation
in the ADC output codes over a 2000 point sampling interval.
Similar measurements were done for the current channel. For
the temperature channel, a 10 kΩ fixed resistor was connected
instead of a thermistor. The results are shown in Figure 8,
Figure 9, and Figure 10, respectively.
2201
2001
1801
1601
1401
1201
1001
801
601
401
201
1
0.95
SAMPLING INTERVAL
Figure 9. Current Noise Measured with Battery Connections Shorted
(140 μA p-p Current Noise)
Rev. A | Page 7 of 10
CN-0352
Circuit Note
25.510
CIRCUIT EVALUATION AND TEST
Warning
This evaluation system interfaces to lithium ion batteries, which
can be damaged, catch on fire, or explode if overcharged, overdischarged, or subjected to source or sink currents that exceed
the specifications of the battery manufacturer. Take all necessary
steps to protect users during operation.
25.500
25.495
The CN-0352 evaluation software on the PC communicates with
the EVAL-CN0352-EB1Z hardware to capture and analyze data
from the EVAL-CN0352-EB1Z circuit board.
12842-010
25.490
Equipment Needed
2201
2001
1801
1601
1401
1201
1001
801
601
401
201
1
25.485
The following equipment is needed:






SAMPLING INTERVAL
Figure 10. Thermistor Noise Measured with 10 kΩ Resistor
(0.014°C p-p Noise)
A typical lithium ion battery charge and discharge profile is
shown in Figure 11.
5.0
4.5
3000
VOLTAGE
CAPACITY
2000
3.5
3.0
CURRENT
Getting Started
CURRENT (mA)
CAPACITY (mAh)
VOLTAGE (V)
4.0
Detailed operation of the evaluation hardware and software is
contained in the CN-0352 User Guide, which can be found at
www.analog.com/CN0352-UserGuide.
Functional Diagram
1000
A functional block diagram of the test setup is shown in
Figure 12
2.5
0
50
100
150
0
200
12842-011
2.0
EVAL-CN0352-EB1Z circuit evaluation board system
5 V, 3 A or higher dc power supply or wall wart
PC or laptop with USB Port
USB to RS485 adapter supporting baud rate of 115,200 bps
CN-0352 evaluation software (see the CN-0352 User Guide)
Li-ion battery samples and battery holder (for safety
consideration, using the Li-ion battery with protection
circuit integrated is highly recommended)
TIME (Minutes)
PC
USB
Figure 11. Typical Charging and Discharging Profile
COMMON VARIATIONS
The ADP5061 and ADP5062 are both linear battery chargers
with management functions for charging current up to 2 A. The
ADP5062 is available in a 4 mm × 4 mm LFCSP package.
The ADG714 is an octal, single-pole/single-throw (SPST) switch
with a QSPI™-compatible interface. The SPI clock of ADG714
can be much higher than the 400 kHz upper limit of the I2C bus.
The channel switching time is therefore much shorter than that
of the ADG715, and the ADG714 is a better choice for systems
with 16 or 32 battery channels.
A complete set of documentation for the EVAL-CN0352-EB1Z
board, including complete schematic, MCU source code, layout
drawings, Gerber files, and bill of materials are available in the
CN-0352 Design Support Package at
www.analog.com/CN0352-DesignSupport.
Rev. A | Page 8 of 10
RESET
USB TO RS-485 ADAPTER
PWM
FAN2
PWM
FAN1
FAN2
FAN1
5V DC
POWER
RS-485
COM
PWR
EVAL-CN0352-EB1Z
BAT1 BAT2 BAT3
BAT4 BAT5 BAT6 BAT7
Figure 12. Test Setup Functional Diagram
BAT8
12842-012
TEMPERATURE (°C)
25.505
Circuit Note
CN-0352
FPWR
Setup
FAN1 AND FAN2
VFAN
PGND
FAN SPEED FEEDBACK
PWM CONTROL
Figure 13. Fan Connections
Plug the USB port of USB to RS485 adapter to the USB port on
the PC and connect the RS485 side to the terminal block of the
MCU board marked COM.
Turn on the 5 V dc power supply and the fan power supply,
then connect the Li-ion battery to the input/output board.
The CN-0352 Software User Guide provides information and
details regarding the test setup and how to use the evaluation
software for gathering the test data and analyzing the result.
12842-014
The header marked FAN1, FAN2, and FPWR are for connecting
to the fans. The pin definitions are shown in Figure 13.
Carefully verify the pin connections of the fans. Typical power
for a PWM controlled fan is 12 V. The acceptable range of
VFAN is 0 V to 15 V. Connect the VFAN to the external dc fan
power supply.
VFAN
PGND
12842-013
Plug the MCU board (EVAL-CN0352-EB1Z_MCU) and the
input/output boards (EVAL-CN0352-EB1Z_I/O) into the
connector on the base board (EVAL-CN0352-EB1Z_BAS), as
shown in Figure 12. With the 5 V power supply off, connect the
5 V dc power supply to the terminal block marked PWR. The
fans for cooling the heat sink on the input/output board are
necessary but not included into the packaging box.
Figure 14. Complete Battery Testing System Connected to Eight Batteries
Rev. A | Page 9 of 10
CN-0352
Circuit Note
LEARN MORE
Data Sheets and Evaluation Boards
CN-0352 Design Support Package:
www.analog.com/CN0352-DesignSupport.
CN-0352 Evaluation System (EVAL-CN0352-EB1Z)
“Battery Chargers,” Chapter 5 in Power and Thermal
Management, Analog Devices, 1998.
ADG715 Data Sheet
MT-031 Tutorial. Grounding Data Converters and Solving the
Mystery of AGND and DGND. Analog Devices.
AD8237 Data Sheet
MT-101 Tutorial. Decoupling Techniques. Analog Devices.
ADP5065 Data Sheet
AD8601 Data Sheet
AD8275 Data Sheet
AD8276 Data Sheet
ADuCM360 Data Sheet
REVISION HISTORY
3/16—Rev. 0 to Rev. A
Changes to Circuit Evaluation and Test Section ...........................8
1/16—Revision 0: Initial Version
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CN12842-0-3/16(A)
Rev. A | Page 10 of 10