The DS1858 dual temperature-controlled nonvolatile
(NV) variable resistors with three monitors consists of
two 50kΩ 256-position linear variable resistors, three
analog monitor inputs (MON1, MON2, MON3), and a
direct-to-digital temperature sensor. The device pro-
vides an ideal method for setting and temperature-com-
pensating bias voltages and currents in control
applications using minimal circuitry. The variable resis-
tor settings are stored in EEPROM memory and can be
accessed over the 2-wire serial bus.
Applications
Optical Transceivers
Optical Transponders
Instrumentation and Industrial Controls
RF Power Amps
Diagnostic Monitoring
Typical Operating Circuit
PART
DS1858E-050
V
CC
V
CC
= 3.3V
4.7kΩ
2-WIRE
INTERFACE
Tx-FAULT
4.7kΩ
1
2
3
4
5
LOS
GROUND TO
DISABLE WRITE
PROTECT
6
7
8
SDA
SCL
OUT1
IN1
OUT2
IN2
WPEN
GND
V
CC
H1
L1
16
15
14
Ordering Information
TEMP RANGE PIN-PACKAGE
-40°C to +95°C 16 TSSOP
-40°C to +95°C 16 TSSOP
-40°C to +95°C
16 TSSOP
(Tape-and-Reel)
DS1858E-050+
DS1858E-050/T&R
0.1µF
DECOUPLING
CAP
DS1858B-050
-40°C to +95°C 16-Ball CSBGA
TO LASER BIAS
CONTROL
TO LASER
MODULATION
CONTROL
+Denotes
lead-free package.
DS1858
13
H0
12
L0
MON3
MON2
MON1
Pin Configurations
TOP VIEW
1 SDA
2 SCL
B
OUT2
SDA
H0
3 OUT1
L1
4 IN1
C
WPEN
IN2
OUT1
5 OUT2
MON3
6 IN2
7 WPEN
MON2
4
8 GND
V
CC
16
H1 15
L1 14
H0 13
11 Tx POWER*
10 Rx POWER*
9 Tx BIAS*
DIAGNOSTIC
INPUTS
0 TO 2.5V FS
A
IN1
SCL
V
CC
H1
*Rx POWER, Tx BIAS, AND Tx POWER CAN BE
ARBITRARILY ASSIGNED TO THE MON INPUTS
DS1858
L0 12
MON3 11
MON2 10
MON1 9
D
GND
1
L0
2
MON1
3
16-BALL CSBGA (4mm x 4mm)
1.0mm PITCH
16 TSSOP
______________________________________________
Maxim Integrated Products
1
For pricing delivery, and ordering information please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Dual Temperature-Controlled
Resistors with Three Monitors
DS1858
ABSOLUTE MAXIMUM RATINGS
Voltage on V
CC
Relative to Ground.......................-0.5V to +6.0V
Voltage on Inputs Relative
to Ground* ................................................-0.5V to V
CC
+ 0.5V
Voltage on Resistor Inputs Relative
to Ground* ................................................-0.5V to V
CC
+ 0.5V
*Not to exceed 6.0V.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Current into Resistors............................................................5mA
Operating Temperature Range ...........................-40°C to +95°C
Programming Temperature Range .........................0°C to +70°C
Storage Temperature Range .............................-55°C to +125°C
Soldering Temperature .......................................See IPC/JEDEC