iC-HL
NON-VOLATILE LASER BIAS POTENTIOMETER
iC-HL is a high-precision 1024-step logarithmic potentiometer for flexible power adjustment of laser diodes with monitor
currents from 7 µA to 1.4 mA. The logarithmic characteristic of
iC-HL guarantees constant power adjustment accuracy in steps
better than 2% (1% typical) over a wide resistance range from
350 Ω to 80 kΩ.
Features
– High-precision programmable logarithmic potentiometer
– Wide resistance range from 350 Ω to 80 kΩ
– Calibration accuracy with resistance steps better 2%
(typical 1%)
– Best APC driver performance (iC-WK series) with monitor
currents of 7 µA to 1.4 mA
– Wireless optical laser power adjustment capability
– Dual-mode programming by optical/electrical coupling
– Simple up/down clock interface to step the resistance
– Internal E²PROM
– Programmable device ID allows for parallel connection of up
to 16 devices
Applications
– Laser diode power adjustment
– Remote power adjustment of laser modules
– Adjustment of encapsulated devices
– Ideal for use with iC-Haus’ laser diode driver family: iC-WK/L,
iC-WKM and iC-WKN
LDA
Suitable lase diodes
(depends on APC)
CLDA
MD LD
LD
MD LD
MD
MDA
MD
LDK
VDD
20 BITS EEPROM REGISTER
=1
EEPROM CONTROLLER
AND
CHARGE PUMP
DIGITAL
FILTER
+
REFH
−
REFL
WE
CI
iC−WK
iC−WKL
iC−WKN
iC−WKM
CI
COMMUNICATION INTERFACE
HYSTERESIS
GENERATOR
MDA
iC−HL
ACK
LD
UPND
10 Bits
SERIAL PROGRAMMING INTERFACE
POWER−DOWN RESET
1 MHz OSCILLATOR
CLK
R
OVERTEMP SHUTDOWN
0
GND
1023
AGND
Am Kuemmerling 18 • D -55294 Bodenheim, Germany
Tel. +49 61 35 / 92 92-30 0 • Fax +49 61 35 / 92 92-19 2 • http://www.ichaus.com
AGND
iC-HL NON-VOLATILE LASER BIAS POTENTIOMETER
iC-HL resistance values can be easily programmed via an
innovative wireless optical system based on the transmission of
modulated light pulses into the laser device monitor diode.
Pin Functions
In addition, programming commands can be sent over a TTLcompatible serial interface. For simple closed loop controlled
systems, an up/down clock interface is also available to ease
laser power adjustment.
Key Specifications
General
No.
Name
Function
1
VDD
3.3 to 5 V Power Supply Voltage
2
ACK
Communication Acknowledge Input
3
UPND
UP/DOWN Selection Input
4
CLK
UP/DOWN Clock Input
5
GND
Ground
6
AGND
Potentiometer Ground
7
MDA
Monitor Diode Anode
8
WE
Write Enable Input
Permissible Supply Voltage
Normal function
EEPROM write cycle
3.3 to 5.5 V
4.75 to 5.5 V
Standby Current in VDD
VDD = 5 V @ 27 °C
700 µA max.
VDD
Voltage at MDA
0.7 V max.
ACK
Pin Configuration TSSOP8 4.4 mm
1
iC−HL
Code
UPND
EEPROM Characteristics
CLK
Data Retention Time
min. 10 years @ 125 °C
Number of Erase/Write Cycles
min. 1000 cycles @ 25 °C
Number of Read Cycles
min. 106 cycles
WE
MDA
AGND
GND
Resistance Characteristic
Programmable Resistor
80000
Maximum Resistor Value
set to max.
54 to 93 kΩ
Minimum Resistor Value
set to min.
190 to 350 Ω
Resistor Increments
typ. 1% per step
Temperature Coefficient
350 ppm/K
70000
Resistance
60000
50000
40000
30000
20000
10000
Up/Down Clock Interface
0
Frequency at CLK pin
5 kHz max.
0
200
400
600
800
1000
Register Value
Application Example
VCC
1
WE
VDD
8
1
GND
SERIAL INTERFACE
EEPROM
2
MDA
ACK
UPND
7
2
CI
8
LDA
7
C4
1uF
100nF
C3
AGND
LDK
J
I
iC−HL
3
iC−WK/L/N
6
+
3
−
AGND
0.5V
6
VCC
C2
1uF
RESISTOR CONTROL
UP/DOWN INTERFACE
4
CLK
GND
5
4
MDK
MDA
5
Am Kuemmerling 18 • D -55294 Bodenheim, Germany
Tel. +49 61 35 / 92 92-30 0 • Fax +49 61 35 / 92 92-19 2 • http://www.ichaus.com
Rev. 1.0