Rainbow Electronics DS1859 User Manual
General description, Applications, Features
DS1859
Dual, Temperature-Controlled Resistors with
Internally Calibrated 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 DS1859 dual, temperature-controlled, nonvolatile
(NV) variable resistors with three monitors consists of
two 50k
Ω or two 20kΩ, 256-position, linear, variable
resistors; three analog monitor inputs (MON1, MON2,
MON3); and a direct-to-digital temperature sensor. The
device provides an ideal method for setting and tem-
perature-compensating bias voltages and currents in
control applications using minimal circuitry. The vari-
able 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
♦ SFF-8472 Compatible
♦ Five Monitored Channels (Temperature, V
CC
,
MON1, MON2, MON3)
♦ Three External Analog Inputs (MON1, MON2, MON3)
That Support Internal and External Calibration
♦ Scalable Dynamic Range for External Analog Inputs
♦ Internal Direct-to-Digital Temperature Sensor
♦ Alarm and Warning Flags for All Monitored
Channels
♦ Two 50kΩ or Two 20kΩ, 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
♦ Operating Temperature Range of -40°C to +95°C
Ordering Information
Rev 1; 11/03
PART
RESISTANCE
PIN-PACKAGE
DS1859E-050
50k
Ω
16 TSSOP
DS1859E-020
20k
Ω
16 TSSOP
DS1859E-050/T&R
50k
Ω
16 TSSOP
(Tape-and-Reel)
DS1859E-020/T&R
20k
Ω
16 TSSOP
(Tape-and-Reel)
DS1859B-050
50k
Ω
16-Ball CSBGA
DS1859B-020
20k
Ω
16-Ball CSBGA
A
TOP VIEW
B
C
D
1
CSBGA (4mm x 4mm)
1.0mm PITCH
TSSOP
3
2
4
MON3
OUT1
IN2
MON1
L0
GND
WPEN
L1
H0
SDA
OUT2
H1
V
CC
SCL
IN1
MON2
DS1859
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
MON3
MON2
MON1
Pin Configurations
DS1859
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
MON3
MON2
MON1
GROUND TO
DISABLE WRITE
PROTECT
Rx POWER*
DIAGNOSTIC
INPUTS
TO LASER
MODULATION
CONTROL
TO LASER BIAS
CONTROL
DECOUPLING
CAP
Tx POWER*
Tx BIAS*
*SATISFIES SFF-8472 COMPATIBILITY
V
CC
V
CC
= 3.3V
4.7k
Ω
4.7k
Ω
Tx-FAULT
LOS
2-WIRE
INTERFACE
Typical Operating Circuit