Rainbow Electronics DS1854 - Manual

DS1854
Dual Temperature-Controlled Resistors with
Two Monitors
______________________________________________ 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.
General Description
The DS1854 dual temperature-controlled nonvolatile
(NV) variable resistors with two monitors consists of two
50k
Ω 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
Rev 0; 1/03
PART TEMP RANGE PIN-PACKAGE
DS1854E-050 -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
A
TOP VIEW
B
C
D
1
16-BALL CSBGA (4mm x 4mm)
1.0mm PITCH
16 TSSOP
3 2 4
MON2 OUT1 IN2
RHIZ L0 GND
WPEN
L1 H0 SDA OUT2
H1 V CC SCL IN1
MON1
DS1854
SDA 1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
SCL
OUT1
IN1
OUT2
IN2
WPEN
GND
V CC
H1
L1
H0
L0
MON2
MON1
RHIZ
Pin Configurations
DS1854
SDA
1
2
3
4
5
6
7
8
16
0.1 µF
15
14
13
12
11
10
9
SCL
OUT1
IN1
OUT2
IN2
WPEN
GND
V CC
H1
L1
H0
L0
MON2
MON1
RHIZ
GROUND TO
DISABLE WRITE
PROTECT
Rx POWER* DIAGNOSTIC
INPUTS
0 TO 2.5V FS
TO LASER
MODULATION
CONTROL
TO LASER BIAS
CONTROL
DECOUPLING
CAP
Tx BIAS*
Tx DISABLE
*Rx POWER AND Tx BIAS CAN BE ARBITRARILY
ASSIGNED TO THE MON INPUTS
V CC
V CC = 3.3V
4.7k Ω 4.7k Ω
TX-FAULT
LOS
2-WIRE
INTERFACE
Typical Operating Circuit