DS1858
Dual Temperature-Controlled Resistors with
Three Monitors
______________________________________________ Maxim Integrated Products
1
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1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
General Description
The DS1858 dual temperature-controlled nonvolatile
(NV) variable resistors with three monitors consists of
two 50k
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 50k, 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
SFF-8472 Compatible
Ordering Information
Rev 0; 1/03
PART
TEMP RANGE
PIN-PACKAGE
DS1858E-050
-40C to +95C 16 TSSOP
DS1858E-050/T&R
-40C to +95C
16 TSSOP
(Tape-and-Reel)
DS1858B-050
-40C to +95C 16-Ball CSBGA
A
TOP VIEW
B
C
D
1
16-BALL CSBGA (4mm x 4mm)
1.0mm PITCH
16 TSSOP
3
2
4
MON3
OUT1
IN2
MON1
L0
GND
WPEN
L1
H0
SDA
OUT2
H1
V
CC
SCL
IN1
MON2
DS1858
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
DS1858
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
Tx POWER*
DIAGNOSTIC
INPUTS
0 TO 2.5V FS
TO LASER
MODULATION
CONTROL
TO LASER BIAS
CONTROL
DECOUPLING
CAP
Rx POWER*
Tx BIAS*
*Rx POWER, Tx BIAS, AND Tx POWER CAN BE
ARBITRARILY ASSIGNED TO THE MON INPUTS
V
CC
V
CC
= 3.3V
4.7k
4.7k
Tx-FAULT
LOS
2-WIRE
INTERFACE
Typical Operating Circuit
DS1858
Dual Temperature-Controlled Resistors with
Three Monitors
2
_____________________________________________________________________
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
V
CC
(Note 1)
3.0
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
V
IH
Input logic 1
1.5
Input Logic Levels (IN1, IN2)
V
IL
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 on V
CC
Relative to Ground.......................-0.5V to +6.0V
Voltage on Inputs Relative
to Ground* ................................................-0.5V to V
CC
+ 0.5V
Voltage 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
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
-1
+1
A
Input Current each I/O Pin
0.4 x V
CC
< V
I/O
< 0.9 x V
CC
-10
+10
A
V
OL1
3mA sink current
0
0.4
Low-Level Output Voltage (SDA)
V
OL2
6mA sink current
0
0.6
V
Full-Scale Input (MON1, MON2,
MON3)
(Note 4)
2.4875
2.5
2.5125
V
Full-Scale V
CC
Monitor
(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
V
OL1
3mA sink current
0
0.4
V
OUT1, OUT2 Voltage
V
OL2
6mA sink current
0
0.6
V
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
= 3.0V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
*Not to exceed 6.0V.
DS1858
Dual Temperature-Controlled Resistors with
Three Monitors
_____________________________________________________________________
3
PARAMETER
SYMBOL
CONDITIONS
TYP
MAX
UNITS
Thermometer Error
T
ERR
-40C to +95C
3.0
C
DIGITAL THERMOMETER
(V
CC
= 3.0V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Resolution
VMON
610
V
Supply Resolution
V
CC
1.6
mV
Input/Supply Accuracy
A
CC
0.25
0.5
% FS
(full scale)
Update Rate for MON1, MON2,
MON3, Temp, or V
CC
t
frame
25
36
ms
ANALOG VOLTAGE MONITORING
(V
CC
= 3.0V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Position 00h Resistance
T
A
= +25C
0.7
1.0
1.25
k
Position FFh Resistance
T
A
= +25C
40
50
60
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
= 3.0V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
DS1858
Dual Temperature-Controlled Resistors with
Three 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
ms
AC ELECTRICAL CHARACTERISTICS
(V
CC
= 3.0V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
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: The maximum voltage the MON inputs will read is approximately 2.5V, even if the voltage on the inputs is greater than 2.5V.
Note 5:
This voltage is defining the maximum range of the analog-to-digital converter voltage and 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.
DS1858
Dual Temperature-Controlled Resistors with
Three Monitors
_____________________________________________________________________
5
AC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.0V to 5.5V, T
A
= -40C to +95C, unless otherwise noted.)
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) in order
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: EEPROM write begins after a STOP condition occurs.
Typical Operating Characteristics
(V
CC
= 5.0V, T
A
= +25C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
DS1858 toc01
TEMPERATURE (
C)
SUPPLY CURRENT (
A)
80
60
40
20
0
-20
540
580
620
660
700
500
-40
100
SUPPLY CURRENT vs. VOLTAGE
DS1858 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
RESISTANCE vs. SETTING
DS1858 toc03
SETTING
RESISTANCE (k
)
250
200
150
100
50
10
20
30
40
50
60
0
0
300
ACTIVE SUPPLY CURRENT
vs. SCL FREQUENCY
DS1858 toc04
SCL FREQUENCY (kHz)
ACTIVE SUPPLY CURRENT (
A)
300
200
100
540
580
620
660
700
SDA = 5V
500
0
400
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