DS1854 Datasheet, PDF (1/22 Pages) Maxim Integrated Products – Dual Temperature-Controlled Resistors with Two Monitors

Rev 0; 1/03
Dual Temperature-Controlled Resistors with
Two Monitors
General Description
The DS1854 dual temperature-controlled nonvolatile
(NV) variable resistors with two monitors consists of two
50kΩ 256-position linear variable resistors, two analog
monitor inputs (MON1, MON2), and a direct-to-digital
temperature sensor. The device provides an ideal
method for setting and temperature-compensating bias
voltages and currents in control applications using min-
imal circuitry. The variable resistor 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
♦ Four Total Monitored Channels (Temperature,
V_CC, MON1, MON2)
♦ Two External Analog Inputs (MON1, MON2)
♦ 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
♦ Resistor Disable (Open-Circuit) Function
♦ 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
Ordering Information
PART
DS1854E-050
TEMP RANGE PIN-PACKAGE
-40°C to +95°C 16 TSSOP
DS1854E-050/T&R
-40°C to +95°C
16 TSSOP
(Tape-and-Reel)
DS1854B-050
-40°C to +95°C 16-Ball CSBGA
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
DS1854
16
V_CC
H1 ¹⁵
14
L1
13
H0
12
L0
0.1µF
DECOUPLING
CAP
TO LASER BIAS
CONTROL
TO LASER
MODULATION
CONTROL
11 Rx POWER*
MON2
10 _{Tx BIAS*}
MON1
RHIZ ^{9 Tx DISABLE}
DIAGNOSTIC
INPUTS
0 TO 2.5V FS
*Rx POWER AND Tx BIAS CAN BE ARBITRARILY
ASSIGNED TO THE MON INPUTS
Pin Configurations
TOP VIEW
A
IN1
SCL VCC
1 SDA
H1
2 SCL
V_CC 16
H1 15
B _{OUT2 SDA}
H0
3 OUT1
L1
4 IN1
L1 14
H0 13
5 OUT2 ^DS1854
C _{WPEN IN2 OUT1 MON2}
L0 12
6 IN2
MON2 11
7 WPEN
D GND L0 RHIZ _MON1
8 GND
MON1 10
RHIZ ₉
1
2
3
4
16-BALL CSBGA (4mm x 4mm)
1.0mm PITCH
16 TSSOP
______________________________________________ Maxim Integrated Products 1
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