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
or two 20k, 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 50k or Two 20k, Linear, 256-Position,
Nonvolatile Temperature-Controlled Variable
Resistors
Resistor Settings Changeable Every 2C
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 -40C to +95C
Ordering Information
Rev 1; 11/03
PART
RESISTANCE
PIN-PACKAGE
DS1859E-050
50k
16 TSSOP
DS1859E-020
20k
16 TSSOP
DS1859E-050/T&R
50k
16 TSSOP
(Tape-and-Reel)
DS1859E-020/T&R
20k
16 TSSOP
(Tape-and-Reel)
DS1859B-050
50k
16-Ball CSBGA
DS1859B-020
20k
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
F
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
4.7k
Tx-FAULT
LOS
2-WIRE
INTERFACE
Typical Operating Circuit
DS1859
Dual, Temperature-Controlled Resistors with
Internally Calibrated Monitors
2
_____________________________________________________________________
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
V
CC
(Note 1)
2.97
5.5
V
Input Logic 1 (SDA, SCL, WPEN)
V
IH
(Note 2)
0.7 x Vcc
V
CC
+ 0.3
V
Input Logic 0 (SDA, SCL, WPEN)
V
IL
(Note 2)
-0.3
+0.3 x V
CC
V
Resistor Inputs (L0, L1, H0, H1)
-0.3
V
CC
+ 0.3
V
Resistor Current
I
RES
-3
+3
mA
High-Z Resistor Current
I
ROFF
0.001
0.1
A
Input logic 1
1.5
Input Logic Levels (IN1, IN2)
Input logic 0
0.9
V
ABSOLUTE MAXIMUM RATINGS
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.
Voltage Range on V
CC
Relative to Ground ...........-0.5V to +6.0V
Voltage Range on Inputs Relative
to Ground* ................................................-0.5V to V
CC
+ 0.5V
Voltage Range on Resistor Inputs Relative
to Ground* ................................................-0.5V to V
CC
+ 0.5V
Current into Resistors............................................................5mA
Operating Temperature Range ...........................-40C to +95C
Programming Temperature Range .........................0C to +70C
Storage Temperature Range .............................-55C to +125C
Soldering Temperature .......................................See IPC/JEDEC
J-STD-020A
RECOMMENDED DC OPERATING CONDITIONS
(T
A
= -40C to +95C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current
I
CC
(Note 3)
1
2
mA
Input Leakage
I
IL
-200
+200
nA
V
OL1
3mA sink current
0
0.4
Low-Level Output Voltage
(SDA, OUT1, OUT2)
V
OL2
6mA sink current
0
0.6
V
Full-Scale Input (MON1, MON2,
MON3)
At factory setting
(Note 4)
2.4875
2.5
2.5125
V
Full-Scale V
CC
Monitor
At factory setting
(Note 5)
6.5208
6.5536
6.5864
V
I/O Capacitance
C
I/O
10
pF
WPEN Pullup
R
WPEN
40
65
100
k
Digital Power-On Reset
POD
1.0
2.2
V
Analog Power-On Reset
POA
2.0
2.6
V
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.97V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
*Not to exceed 6.0V.
DS1859
Dual, Temperature-Controlled Resistors with
Internally Calibrated Monitors
_____________________________________________________________________
3
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Thermometer Error
T
ERR
-40C to +95C
3.0
C
DIGITAL THERMOMETER
(V
CC
= 2.97V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
EEPROM Writes
+70C
50,000
NONVOLATILE MEMORY CHARACTERISTICS
(V
CC
= 2.97V to 5.5V)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Resolution
VMON
610
V
Supply Resolution
V
CC
1.6
mV
Input/Supply Accuracy
(MON1, MON2, MON3, V
CC
)
A
CC
At factory setting
0.25
0.5
% FS
(full scale)
Update Rate for MON1, MON2,
MON3, Temp, or V
CC
t
frame
30
45
ms
Input/Supply Offset
(MON1, MON2, MON3, V
CC
)
V
OS
(Note 14)
0
5
LSB
ANALOG VOLTAGE MONITORING
(V
CC
= 2.97V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Position 00h Resistance (50k
)
T
A
= +25C
0.65
1.0
1.35
k
Position FFh Resistance (50k
)
T
A
= +25C
40
50
60
k
Position 00h Resistance (20k
)
T
A
= +25C
0.20
0.40
0.55
k
Position FFh Resistance (20k
)
T
A
= +25C
16
20
24
k
Absolute Linearity
(Note 6)
-2
+2
LSB
Relative Linearity
(Note 7)
-1
+1
LSB
Temperature Coefficient
(Note 8)
50
ppm/C
ANALOG RESISTOR CHARACTERISTICS
(V
CC
= 2.97V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
DS1859
Dual, Temperature-Controlled Resistors with
Internally Calibrated Monitors
4
_____________________________________________________________________
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Fast mode (Note 9)
0
400
SCL Clock Frequency
f
SCL
Standard mode (Note 9)
0
100
kHz
Fast mode (Note 9)
1.3
Bus Free Time Between STOP and
START Condition
t
BUF
Standard mode (Note 9)
4.7
s
Fast mode (Notes 9, 10)
0.6
Hold Time (Repeated)
START Condition
t
HD:STA
Standard mode (Notes 9, 10)
4.0
s
Fast mode (Note 9)
1.3
LOW Period of SCL Clock
t
LOW
Standard mode (Note 9)
4.7
s
Fast mode (Note 9)
0.6
HIGH Period of SCL Clock
t
HIGH
Standard mode (Note 9)
4.0
s
Fast mode (Notes 9, 11, 12)
0
0.9
Data Hold Time
t
HD:DAT
Standard mode (Notes 9, 11, 12)
0
s
Fast mode (Note 9)
100
Data Setup Time
t
SU:DAT
Standard mode (Note 9)
250
ns
Fast mode (Note 9)
0.6
START Setup Time
t
SU:STA
Standard mode (Note 9)
4.7
s
Fast mode (Note 13)
20 + 0.1C
B
300
Rise Time of Both SDA and SCL
Signals
t
R
Standard mode (Note 13)
20 + 0.1C
B
1000
ns
Fast mode (Note 13)
20 + 0.1C
B
300
Fall Time of Both SDA and SCL
Signals
t
F
Standard mode (Note 13)
20 + 0.1C
B
300
ns
Fast mode
0.6
Setup Time for STOP Condition
t
SU:STO
Standard mode
4.0
s
Capacitive Load for Each Bus Line
C
B
(Note 13)
400
pF
EEPROM Write Time
t
W
(Note 14)
10
20
ms
AC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.97V to 5.5V, T
A
= -40C to +95C, unless otherwise noted. See Figure 6.)
Note 1:
All voltages are referenced to ground.
Note 2: I/O pins of fast-mode devices must not obstruct the SDA and SCL lines if V
CC
is switched off.
Note 3:
SDA and SCL are connected to V
CC
and all other input signals are connected to well-defined logic levels.
Note 4: Full Scale is user programmable. The maximum voltage that the MON inputs read is approximately Full Scale, even if the volt-
age on the inputs is greater than Full Scale.
Note 5:
This voltage defines the maximum range of the analog-to-digital converter voltage, not the maximum V
CC
voltage.
Note 6: Absolute linearity is the difference of measured value from expected value at DAC position. The expected value is a
straight line from measured minimum position to measured maximum position.
Note 7: Relative linearity is the deviation of an LSB DAC setting change vs. the expected LSB change. The expected LSB change
is the slope of the straight line from measured minimum position to measured maximum position.
Note 8: See the Typical Operating Characteristics.
Note 9: A fast-mode device can be used in a standard-mode system, but the requirement t
SU:DAT
> 250ns must then be met. This
is automatically the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the
LOW period of the SCL signal, it must output the next data bit to the SDA line t
RMAX
+ t
SU:DAT
= 1000ns + 250ns = 1250ns
before the SCL line is released.
DS1859
Dual, Temperature-Controlled Resistors with
Internally Calibrated Monitors
_____________________________________________________________________
5
Note 10: After this period, the first clock pulse is generated.
Note 11: The maximum t
HD:DAT
only has to be met if the device does not stretch the LOW period (t
LOW
) of the SCL signal.
Note 12: A device must internally provide a hold time of at least 300ns for the SDA signal (see the V
IH MIN
of the SCL signal) to
bridge the undefined region of the falling edge of SCL.
Note 13: C
B
--total capacitance of one bus line, timing referenced to 0.9 x V
CC
and 0.1 x V
CC
.
Note 14: Guaranteed by design.
Typical Operating Characteristics
(V
CC
= 5.0V, T
A
= +25C, for both 50k
and 20k versions, unless otherwise noted.)
TEMPERATURE (
C)
40
60
80
20
0
-20
560
600
640
680
720
520
-40
100
SUPPLY CURRENT vs. TEMPERATURE
DS1859 toc01
SUPPLY CURRENT (
A)
SDA = SCL = V
CC
SUPPLY CURRENT vs. VOLTAGE
DS1859 toc02
VOLTAGE (V)
SUPPLY CURRENT (
A)
5.0
4.5
4.0
3.5
450
500
550
600
650
700
400
3.0
5.5
SDA = SCL = V
CC
RESISTANCE vs. SETTING
DS1859 toc03
SETTING (DEC)
RESISTANCE (k
)
200
150
100
50
10
20
30
40
50
60
0
0
250
50k
VERSION
RESISTANCE vs. SETTING
DS1859 toc04
SETTING (DEC)
RESISTANCE (k
)
200
150
100
50
5
10
15
20
0
0
250
20k
VERSION
ACTIVE SUPPLY CURRENT
vs. SCL FREQUENCY
DS1859 toc05
SCL FREQUENCY (kHz)
ACTIVE SUPPLY CURRENT (
A)
300
200
100
600
640
680
720
760
560
0
400
SDA = V
CC
RESISTOR 0 INL (LSB)
DS1859 toc06
SETTING (DEC)
RESISTOR 0 INL (LSB)
225
200
150 175
50 75 100 125
25
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
0
250
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