DS1858 Datasheet, PDF (1/22 Pages) Maxim Integrated Products – Dual Temperature-Controlled Resistors with Three Monitors

Rev 0; 1/03
Dual Temperature-Controlled Resistors with
Three Monitors
General Description
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
Features
♦ Five Total Monitored Channels (Temperature,
V_CC, MON1, MON2, MON3)
♦ Three External Analog Inputs (MON1, MON2,
MON3)
♦ Internal Direct-to-Digital Temperature Sensor
♦ Two 50kΩ, Linear, 256-Position, Nonvolatile
Temperature-Controlled Variable Resistors
♦ Resistor Settings Changeable Every 2°C
♦ Access to Monitoring and ID Information
Configurable with Separate Device Addresses
♦ 2-Wire Serial Interface
♦ Two Buffers with TTL/CMOS-Compatible Inputs
and Open-Drain Outputs
♦ Operates from a 3.3V or 5V Supply
♦ SFF-8472 Compatible
Typical Operating Circuit
V_CC
4.7kΩ
2-WIRE
INTERFACE
Tx-FAULT
LOS
GROUND TO
DISABLE WRITE
PROTECT
V_CC = 3.3V
4.7kΩ
1
SDA
2
SCL
3
OUT1
4
IN1
5
OUT2
6
IN2
7
WPEN
8
GND
DS1858
16
V_CC
H1 ¹⁵
14
L1
13
H0
L0 ¹²
0.1µF
DECOUPLING
CAP
TO LASER BIAS
CONTROL
TO LASER
MODULATION
CONTROL
11 Tx POWER*
MON3
10 _{Rx POWER*}
MON2
MON1 ^{9 Tx BIAS*}
DIAGNOSTIC
INPUTS
0 TO 2.5V FS
*Rx POWER, Tx BIAS, AND Tx POWER CAN BE
ARBITRARILY ASSIGNED TO THE MON INPUTS
Ordering Information
PART
DS1858E-050
TEMP RANGE PIN-PACKAGE
-40°C to +95°C 16 TSSOP
DS1858E-050/T&R -40°C to +95°C ^{16 TSSOP}
(Tape-and-Reel)
DS1858B-050
-40°C to +95°C 16-Ball CSBGA
Pin Configurations
TOP VIEW
A _IN1
SCL VCC
H1
B _{OUT2 SDA}
H0
L1
C _{WPEN IN2 OUT1 MON3}
D GND L0 MON1 _MON2
1
2
3
4
16-BALL CSBGA (4mm x 4mm)
1.0mm PITCH
1 SDA
2 SCL
3 OUT1
4 IN1
5 OUT2
6 IN2
7 WPEN
8 GND
V_CC 16
H1 15
L1 14
DS1858
H0 13
L0 12
MON3 11
MON2 10
MON1 ₉
16 TSSOP
______________________________________________ Maxim Integrated Products 1
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