Advanced Power
Electronics Corp.
APE1502
2.5V to 5.5V Input Voltage Range
Output Voltage from 0.6V to VIN
1.4MHz Constant Frequency Operation
Up to 1A Output Current
High Efficiency : Up to 96%
No Schottky Diode Required
Quiescent Current: 250uA (Typical)
Current Mode Operation for Excellent Line
and Load Transient Response
Current Limit, Enable Function
Short Circuit Protect (SCP)
Build in Soft Start Function
< 1µA Shutdown Current
SOT-23-5L and TDFN 2x2-6L Pb-Free
Packages Type
Halogen Free Product
V
IN
= 2.5V~5.5V
C1
4.7u
U1
VIN
SW
EN
FB
GND
APE1502
L1
2.2uH
R1
600 K
V
OUT
= 0.6 x (1+R1/R2 )
R2= 100K~ 330K
R2
300 K
APE1502 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version. Supply current with no load is 250uA and drops to <1uA in shutdown. The 2.5V to 5.5V input voltage range makes APE1502 ideally suited for single
Li-Ion, two to three AA battery-powered applications.
100% duty cycle provides low dropout operation, extending battery life in portable systems.
PWM operation provides very low output ripple voltage for noise sensitive applications. Switching frequency is internally set at 1.4MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and decreases need of an external schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. APE1502 is available in small TSOT-23-5L and
TDFN 2x2-6L packages.
C3
15p
V
OUT
= 1.8V
C2
10u
APE1502X
Package Type
TY5 : TSOT-23-5L
TGN2 : TDFN 2x2-6L
Data and specifications subject to change without notice 1
20130823V7.2

Advanced Power
Electronics Corp.
VIN PIN Voltage (V
IN
) -------------------------------------- V
SS
- 0.3V to V
SS
+ 6.5V
Feedback Pin Voltage (V
FB
) ------------------------------ V
SS
- 0.3V to V
IN
+ 0.3V
EN Pin Voltage (V
EN
) --------------------------------------- V
SS
- 0.3V to V
IN
+ 0.3V
Switch Pin Voltage (V
SW
) --------------------------------- V
SS
- 0.3V to V
IN
+ 0.3V
Peak SW Sink & Source Current (I
PSW
) --------------- 1.4A
Power Dissipation (PD) ----------------------------------- ( T
J
-T
A
) / Rthja mW
Storage Temperature Range (T
ST
) --------------------- -40 to +150°C
Operating Temperature Range (T
OP
) ------------------ -40 to +85°C
Junction Temperature (T
J
) -------------------------------- +125°C
Thermal Resistance from Junction to case
TSOT-23-5L 110°C/W
TDFN 2x2-6L 25°C/W
TSOT-23-5L 250°C/W
TDFN 2x2-6L 120°C/W
APE1502
Note1 : Rthja is measured with the PCB copper area of approximately 1 in
2
(Multi-layer). That need connect to GND pin or exposed pad (APE1502TGN2).
FB GND SW FB VIN
5 4
6 5 4
GND
(Top View)
TSOT-23-5L
1 2 3
NC EN VIN
TDFN 2x2-6L
1 2 3
EN GND SW
(V
IN
= V
EN
=3.6V, T
A
=25 o
C, unless otherwise specified)
Parameter
Input Voltage Range
Feedback Voltage
Feedback Bias Current
Quiescent Current
Shutdown Supply Current
Switching Current Limit
Line Regulation
Load Regulation
Oscillation Frequency
R
DS(ON) of P-CH MOSFET
R
DS(ON) of N-CH MOSFET
SYM
V
IN
TEST CONDITION
V
FB
I
FB
I
CCQ
I
SD
I
LIMIT
△ V
OUT
/V
OUT
△ V
OUT
/V
OUT
F
OSC
R
DSON
R
DSON
T
A
= +25°C
-40°C < T
A
< 85°C
V
FB
=0.65V
V
V
FB
EN
=1V
=0V
V
IN
= 2.5V to 5.5V
I
OUT
= 0.01 to 1A
SW pin
V
FB
= 0V, I
OUT
= 0.5A
(Note 1)
MIN
2.5
0.588
0.582
-
-
-
1.2
-
-
1.1
-
-
TYP
-
0.6
0.6
-
250
0.1
1.4
0.04
0.5
1.4
0.3
0.25
MAX UNITS
6 V
0.612
V
0.618
+30 nA
350
1
-
0.4
-
1.7
uA uA
A
%/V
%
0.4
0.35
MHz
Ω
Ω
2

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Electronics Corp.
Parameter
EN Pin Logic Input Threshold
Voltage
EN Pin Input Current
Efficiency
Thermal Shutdown
Thermal Shutdown Hysteresis
SYM
V
ENL
V
ENH
I
EN
EFFI
T
DS
T
SH
TEST CONDITION
V
IN
=5V, V
OUT
=3.3V, I
OUT
=0.5A
Note 1: Guaranteed by design.
APE1502
-
-
-
-
MIN TYP MAX UNITS
-
1.5
-
-
0.4
-
V
+0.1
94
140
30
+1
-
-
uA
%
°C
°C
PIN SYMBOL
VIN
EN
SW
GND
NC
FB
PIN DESCRIPTION
Power Supply Input Pin
Enable Pin.
H : Normal Operation
L : Shutdown
Switch output pin. Connect external inductor here. Minimize trace area at this pin to reduce EMI.
Ground Pin
No connect
Output Feedback Pin
VIN
FB
REF
0.6V
Soft-Star
+
-
+
-
OSC
Icomp
SLOPE
COMP
Isense
AMP
-
+
SET
RESET PWM
LOGIC
NON-OVERLAP
CONTROL
SW
GND
Over-Temperature and
Short-Circuit Protection
Enable Logic
EN
3

Advanced Power
Electronics Corp.
APE1502
APE1502 is a monolithic switching mode step-down DC-DC converter. It utilizes internal
MOSFETs to achieve high efficiency and can generate very low output voltage by using internal reference at 0.6V. It operates at a fixed switching frequency, and uses the slope compensated current mode architecture. This step-down DC-DC Converter supplies minimum 1000mA output current at input voltage range from 2.5V to 5.5V.
Slope compensated current mode PWM control provides stable switching and cycle-bycycle current limit for excellent load and line transient responses and protection of the internal main switch (P-Ch MOSFET) and synchronous rectifier (N-CH MOSFET). During normal operation, the internal P-Ch MOSFET is turned on for a certain time to ramp the inductor current at each rising edge of the internal oscillator, and switched off when the peak inductor current is above the error voltage. The current comparator, ICOMP, limits the peak inductor current. When the main switch is off, the synchronous rectifier will be turned on immediately and stay on until either the inductor current starts to reverse, as indicated by the current reversal comparator, I
ZERO
, or the beginning of the next clock cycle.
Application circuit item shows the basic application circuit with APE1502 adjustable output version. The external resistor sets the output voltage according to the following equation:
V
OUT
0 .
6 V
⎝
1
R 1
R 2
Table 1 Resistor select for output voltage setting
V
OUT
R2 R1
1.2V
1.5V
1.8V
300K
300K
300K
300K
450K
600K
2.5V
3.3V
150K
120K
470K
540K
For most designs, the APE1502 operates with inductors of 2.2µH to 3.3µH. Low inductance values are physically smaller but require faster switching, which results in some efficiency loss.
The inductor value can be derived from the following equation:
L
V
V
OUT
IN
(
V
∆
I
IN
L
V f
OUT
OSC
)
Where is inductor Ripple Current. Large value inductors lower ripple current and small value inductors result in high ripple currents. Choose inductor ripple current approximately 20% of the maximum load current 1000mA, Δ I
L
=200mA.
Table 2 Inductor select for output voltage setting (V
IN
=3.6V)
V
OUT
1.2V
1.5V
1.8V
2.5V
Inductor 2.7uH
2.7uH
2.7uH
2.2uH
Part Number WE-TPC 7440430027 7440430027 7440430027 7440430022
Note: Part type MH or M (www.we-online.com)
4

Advanced Power
Electronics Corp.
APE1502
For output voltages above 2.0V, when light-load efficiency is important, the minimum recommended inductor is 2.2 µ H. For optimum voltage-positioning load transients, choose an inductor with DC series resistance in the 50m Ω to 150m Ω range. For higher efficiency at heavy loads (above 200mA), or minimal load regulation (but some transient overshoot), the resistance should be kept below 100m Ω . The DC current rating of the inductor should be at least equal to the maximum load current plus half the ripple current to prevent core saturation (1000mA+100mA).
The input capacitor reduces the surge current drawn from the input and switching noise from the device. The input capacitor impedance at the switching frequency shall be less than input source impedance to prevent high frequency switching current passing to the input. A low ESR input capacitor sized for maximum RMS current must be used. Ceramic capacitors with X5R or
X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. A 4.7µF ceramic capacitor for most applications is sufficient.
The output capacitor is required to be 10uF to keep the output voltage ripple small and to ensure regulation loop stability. The output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or X7R dielectrics are recommended due to their low ESR and high ripple current.
The compensation capacitors for increasing phase margin provide additional stability. It is required 15pF, Please refer to Demo Board Schematic to design.
TSOT-23-5L
C1's ground must be as closer to IC's GND pin as possible
C2, R1 and R2 must be as closer to IC's FB pin as possible
C2
GND
R1
VIN
C1
FB
5
VIN
4
R2
APE1502TY5
VIN
SW should be connected to Inductor by wide and short trace, keep sensitive components away from this trace
1 2 3
EN GND SW
GND
L1
C2's ground must be as closer to IC's GND pin as possible
C2
VOUT
TDFN 2x2-6L
C2, R1 and R2 must be as closer to IC's FB pin as possible and keep the switching trace away.
SW should be connected to Inductor by wide and short trace, keep sensitive components away from this trace
R2
C2 R1
FB
6
GND SW
5 4
L1
VOUT
Expoed Pad
C2
GND
1
NC
2 3
EN VIN
VIN
C1
GND
C1 and C2's ground must be as closer to IC's GND pin as possible
5

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Electronics Corp.
APE1502
6

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Electronics Corp.
APE1502
7

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Electronics Corp.
V
IN
= 5V, V
OUT
= 1.2V, R
LOAD
= No Load V
IN
= 5V, V
OUT
= 1.2V, R
LOAD
= 1 Ω
APE1502
V
IN
= 5V, V
OUT
= 1.2V, R
LOAD
= No Load V
IN
= 5V, V
OUT
= 1.2V
V
IN
= 5V, V
OUT
= 1.2V, I
OUT
= 0.2A ←→ 1A V
IN
= 3.3V, V
OUT
= 1.2V, I
OUT
= 0.2A ←→ 1A
8

Advanced Power
Electronics Corp.
TSOT-23-5L
G6YWS
Part Number : G6
Week:
A~Z : 01~26
a~z : 27~52
ID Code : Internal
Year :
A = 2010
1 = 2011
：
：
TDFN 2x2-6L
Part Number : GB
GB
YWS
Week:
A~Z : 01~26
a~z : 27~52
ID Code : Internal
Year :
A = 2010
1 = 2011
：
：
APE1502
9