Maxim MAX15500GTJ+ Industrial analog current/ voltage-output conditioner Datasheet

19-4602; Rev 1; 2/11
TION KIT
EVALUA BLE
IL
AVA A
Industrial Analog Current/
Voltage-Output Conditioners
The MAX15500/MAX15501 analog output conditioners
provide a programmable current up to Q24mA, or a voltage up to Q12V proportional to a control voltage signal.
The control voltage is typically supplied by an external
DAC with an output voltage range of 0 to 4.096V for the
MAX15500 and 0 to 2.5V for the MAX15501. The output
current and voltage are selectable as either unipolar or
bipolar. In the unipolar configuration, a control voltage
of 5% full-scale (FS) produces a nominal output of 0A or
0V to achieve underrange capability. A control voltage
of 100%FS produces one of two programmable levels
(105%FS or 120%FS) to achieve overrange capability.
The outputs of the MAX15500/MAX15501 are protected
against overcurrent conditions and a short to ground or
supply voltages up to Q35V. The devices also monitor for
overtemperature and supply brownout conditions. The
supply brownout threshold is programmable.
The MAX15500/MAX15501 are programmed through an
SPIK interface capable of daisy-chained operation. The
MAX15500/MAX15501 provide extensive error reporting
through the SPI interface and an additional open-drain
interrupt output. The devices include an analog output to
monitor load conditions.
The MAX15500/MAX15501 operate over the -40NC to
+105NC temperature range. The devices are available in
a 32-pin, 5mm x 5mm TQFN package.
Applications
Programmable Logic Controllers (PLCs)
Distributed I/Os
Embedded Systems
Industrial Control and Automation
AVDDO
REFIN
ERROR
HANDLING
FSMODE
FSSEL
AVSS
AVSSO
32 TQFN-EP*
+2.5V
Note: All devices are specified over the -40NC to +105NC operating temperature range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
SPI is a trademark of Motorola, Inc.
OUTDIS
SENSERN
SENSERP
AVDDO
OUT
COMP
AVSSO
SENSEVN
23
22
21
20
19
18
17
16
N.C.
AVDD 26
15
AGND
AGND 27
14
AIN
SENSERP
AVSS 28
13
REFIN
COMP
MON 29
12
AGND
11
FSMODE
10
FSSEL
9
OUTDIS
OUT
MAX15500
MAX15501
CS1 30
CS2 31
EP*
+
N.C. 32
SENSEVN
DGND
24
SENSEVP 25
SENSERN
SENSEVP
AGND
N.C.
TOP VIEW
*EXPOSED PAD.
1
2
3
4
5
6
7
8
N.C.
MON
+4.096V
MAX15501GTJ+
DVDD
BIDIRECTIONAL
VOLTAGE
DRIVER
ERROR
REFERENCE
32 TQFN-EP*
DGND
ERROR
HANDLING
AIN
OVERCURRENT
PROTECTION
PIN-PACKAGE
ERROR
READY
PART
MAX15500GTJ+
READY
BIDIRECTIONAL
CURRENT
DRIVER
Ordering Information
DOUT
SPI
INTERFACE
±10V
0 to 10V
0 to 5V
±20mA
0 to 20mA
4 to 20mA
S Current Output Drives 0 to 1kI
S Voltage Output Drives Loads Down to 1kI
S HART Compliant
S 2ppm Gain Error Drift Over Temperature
S SPI Interface, with Daisy-Chain Capability
S Supports +4.096V (MAX15500) or +2.5V
(MAX15501) Full-Scale Input Signals
S Extensive Error Reporting
Short-Circuit and Overcurrent Protection
Open-Circuit Detection
Brownout Detection
Overtemperature Protection
S Fast, 40µs Settling Time
DIN
MAX15500
MAX15501
S Programmable Output (Plus Overrange)
SCLK
SCLK
DIN
DOUT
CS1
CS2
AVDD
S Output Protected Up to Q35V
Pin Configuration
Simplified Block Diagram
DVDD
Features
S Supply Voltage Up to Q32.5V
TQFN
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX15500/MAX15501
General Description
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
ABSOLUTE MAXIMUM RATINGS
AVDD to AGND......................................................-0.3V to +35V
AVSS to AGND.......................................................-35V to +0.3V
AVDD to AVSS.............................................................. 0 to +70V
AVDD to AVDDO............................................................ 0 to +4V
AVSS to AVSSO............................................................. -4V to 0V
DGND to AGND....................................................-0.3V to +0.3V
AVDD to DVDD..........................................................-6V to +35V
DVDD to DGND.....................................................-0.3V to +6.0V
CS1, CS2, SCLK, DIN, DOUT, READY, ERROR, FSMODE,
MON, OUTDIS, FSSEL to DGND.......................-0.3V to +6.0V
AIN, REFIN to AGND.............................................-0.3V to +6.0V
SENSEVP, SENSEVN, SENSERP,
SENSERN to AGND. the higher of -35V and (VAVSS - 0.3V) to
the lower of (VAVDD + 0.3V) and +35V
OUT, COMP to AGND... the higher of -35V and (VAVSS - 0.3V) to
the lower of (VAVDD + 0.3V) and +35V
Maximum Current on Pin................................................ ±100mA
Continuous Power Dissipation (derate 34.5mW/NC above +70NC)
32-Pin TQFN (TA = +70NC, multilayer board)..........2758.6mW
Operating Temperature Range......................... -40NC to +105NC
Storage Temperature Range............................. -65NC to +150NC
Lead Temperature (soldering, 10s).................................+300NC
Soldering Temperature (reflow).......................................+260NC
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.
ELECTRICAL CHARACTERISTICS
(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for
the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLY (Note 1)
5% overrange (FSMODE = DVDD)
15
24
32.5
20% overrange (FSMODE = DGND)
18.5
24
32.5
5% overrange (FSMODE = DVDD)
-32.5
-24
-15
20% overrange (FSMODE = DGND)
-32.5
-24
-18.5
Analog Positive Supply Voltage
VAVDD
Analog Negative Supply
Voltage
VAVSS
AVDD to AVDDO Voltage
Difference
VAVDDO
(Note 1)
2.5
V
AVSS to AVSSO Voltage
Difference
VAVSSO
(Note 1)
2.5
V
Digital Supply Voltage
VDVDD
2.7
Analog Positive Supply Current
IAP
IAP = IAVDD + IAVDDO, ILOAD = 0A
Analog Negative Supply Current
IAN
IAN = IAVSS + IAVSSO, ILOAD = 0A
Digital Supply Current
5
-7
V
5.25
V
7
mA
-4.5
0.1
V
mA
IDVDD
VDVDD = 5V
Analog Positive Standby Current
ISTBYP
ISTBYP = IAVDD + IAVDDO, OUTDIS =
DGND or software standby mode
0.4
mA
1
mA
Analog Negative Standby Current
ISTBYN
ISTBYN = IAVSS + IAVSSO, OUTDIS =
DGND or software standby mode
-0.5
mA
ANALOG INPUT (AIN, REFIN)
Input Impedance
RIN
10
kI
Input Capacitance
CIN
10
pF
Analog Input Full Scale
VAIN
REFIN Full-Scale Input
VREFIN
FSSEL = DVDD, MAX15500
4.0
4.096
4.2
FSSEL = DGND, MAX15501
2.4
2.5
2.6
FSSEL = DVDD, MAX15500
4.0
4.096
4.2
FSSEL = DGND, MAX15501
2.4
2.5
2.6
2 _______________________________________________________________________________________
V
V
Industrial Analog Current/
Voltage-Output Conditioners
(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for
the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CURRENT OUTPUT (Note 2)
Maximum Load Resistance
RLOAD
VAVDD = +24V, VAVSS = -24V
750
VAVDD = +32.5V, VAVSS = -32.5V
1000
I
Maximum Load Inductance
LLOAD
CCOMP = 100nF (Note 3)
15
mH
Maximum Load Capacitance
CLOAD
CCOMP = 4.7nF
100
FF
Full-scale step
from 0 to 20mA or
-20mA to + 20mA,
RLOAD = 750I
Maximum Settling Time
1% full-scale step,
RLOAD = 750I
Full-Scale Output Current
IOUT
To 0.1% accuracy,
LLOAD = 20FH,
CCOMP = 0nF
40
To 0.1% accuracy,
LLOAD = 1mH,
CCOMP = 0.15nF
500
To 0.1% accuracy,
LLOAD = 10mH,
CCOMP = 0.15nF
500
To 0.01% accuracy,
LLOAD = 20FH,
CCOMP = 0nF
60
To 0.01% accuracy,
LLOAD = 10mH,
CCOMP = 0.15nF
600
To 0.1% accuracy,
LLOAD = 20FH,
CCOMP = 0nF
20
To 0.1% accuracy,
LLOAD = 1mH,
CCOMP = 0.15nF
100
To 0.1% accuracy,
LLOAD = 10mH,
CCOMP = 0.15nF
100
To 0.01% accuracy,
LLOAD = 20FH,
CCOMP = 0nF
40
To 0.01% accuracy,
LLOAD = 10mH,
CCOMP = 0.15nF
200
Fs
VFSMODE = VDVDD
Q21
VFSMODE = VDGND
Q24
mA
_______________________________________________________________________________________ 3
MAX15500/MAX15501
ELECTRICAL CHARACTERISTICS (continued)
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
ELECTRICAL CHARACTERISTICS (continued)
(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for
the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
VAIN = 5% of VREFIN (unipolar mode),
VAIN = 50% of VREFIN (bipolar mode)
Offset Error
Offset-Error Drift
Gain Error
GE
0.01% precision
RSENSE, tested
according to the
ideal transfer
functions shown in
Table 8
MAX15500
UNITS
Q0.1
Q0.5
%FS
Q0.1
ppm/NC
MAX15501
Q0.1
No RSENSE drift
PSRR
Overcurrent Limit
Q0.5
Q2
ppm/NC
0.05
%FS
(dIOUT/dVOUT), IOUT = 24mA, RLOAD =
750I to 0I, FSMODE = DGND, unipolar
mode
1.0
FA/V
At DC, VAVDD = +24V to +32.5V, VAVSS
= -24V to -32.5V, VAIN = VREFIN, unipolar
mode, FSMODE = DVDD
1.6
FA/V
RSENSE shorted
Output Current Noise
Q0.51
%FS
INL
Output Conductance
Power-Supply Rejection Ratio
MAX
Q5
Gain-Error Drift
Integral Nonlinearity Error
TYP
25
30
40
mA
0.1Hz to 10Hz
20
nARMS
At 1kHz
2.6
Output Slew Rate
1.5
nA/√Hz
mA/Fs
Small-Signal Bandwidth
30
kHz
Maximum OUT Voltage to
AVDDO
VAVDDO - VOUT
2.0
V
Minimum OUT Voltage to
AVSSO
VOUT - VAVSSO
2.0
V
1
kI
CCOMP = 4.7nF
100
FF
To 0.1% accuracy, load = 1kI in parallel
with 1nF, CCOMP = 0nF
20
To 0.1% accuracy, load = 1kI in parallel
with 1FF, CCOMP = 4.7nF
1000
To 0.01% accuracy, load = 1kI in parallel
with 1nF, CCOMP = 0nF
30
VOLTAGE OUTPUT (RLOAD = 1kI)
Minimum Resistive Load
RLOAD
Maximum Capacitive Load
CLOAD
Maximum Settling Time (FullScale Step)
To 0.01% accuracy, load = 1kI in parallel
with 1FF, CCOMP = 4.7nF
Fs
1300
4 _______________________________________________________________________________________
Industrial Analog Current/
Voltage-Output Conditioners
(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for
the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)
PARAMETER
SYMBOL
Maximum Settling Time
(1% Full-Scale Step)
Gain Error
CONDITIONS
MIN
TYP
To 0.1% accuracy, load = 1kI in parallel
with 1nF, CCOMP = 0nF
10
To 0.1% accuracy, load = 1kI in parallel
with 1FF, CCOMP = 4.7nF
300
To 0.01% accuracy, load = 1kI in parallel
with 1nF, CCOMP = 0nF
20
To 0.01% accuracy, load = 1kI in parallel
with 1FF, CCOMP = 4.7nF
600
Tested according to the ideal transfer
functions shown in Table 9
Q0.1
MAX
Fs
Gain-Error Drift
Q0.5
Full-Scale Output Voltage
VOUT
FSMODE = DGND
5V range
5.25
10V range
10.5
5V range
6
10V range
12
VAIN = 5% of VREFIN (unipolar mode),
VAIN = 50% of VREFIN (bipolar mode)
Offset Error
Q0.1
Offset-Error Drift
Integral Nonlinearity Error
Power-Supply Rejection
Output-Voltage Noise
V
Q0.5
%FS
Q2
ppm/NC
0.05
%FS
30
FV/V
0.1Hz to 10Hz
16.3
FVRMS
1kHz
250
nV/√Hz
V/Fs
INL
PSRR
%FS
ppm/NC
Q2
FSMODE = DVDD
UNITS
At DC, VAVDD = +18.5V to +32.5V, VAVSS
= -18.5V to -32.5V, VAIN = VREFIN
Output-Voltage Slew Rate
1.5
Short-Circuit Current
20
30
45
mA
Maximum OUT Voltage to
AVDDO
VAVDDO - VOUT
2.0
V
Minimum OUT Voltage to
AVSSO
VOUT - VAVSSO
2.0
V
_______________________________________________________________________________________ 5
MAX15500/MAX15501
ELECTRICAL CHARACTERISTICS (continued)
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
ELECTRICAL CHARACTERISTICS (continued)
(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for
the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OUTPUT MONITOR (MON)
Maximum Output Voltage
Current mode, see the Output Monitor
section for VMON equations
3
Voltage mode, see the Output Monitor
section for VMON equations
3
V
Output Resistance
35
kI
Overtemperature Threshold
+150
NC
Overtemperature Threshold
Hysteresis
10
NC
OVERTEMPERATURE DETECTION
DIGITAL INPUTS (CS1, CS2, SCLK, DIN, OUTDIS, FSSEL, FSMODE)
Input High Voltage
VIH
Input Low Voltage
VIL
Input Hysteresis
0.7 x
VDVDD
0.3 x
VDVDD
VIHYST
Input Leakage Current
IIN
Input Capacitance
CIN
V
300
VINPUT = 0V or VDVDD
Q0.1
V
mV
Q1.0
10
FA
pF
DIGITAL OUTPUT (DOUT, READY)
Output Low Voltage
VOL
ISINK = 4mA
Output High Voltage
VOH
ISOURCE = 4mA
Output Three-State Leakage
IOZ
DOUT only
Q0.1
Output Three-State Capacitance
COZ
DOUT only
15
pF
Output Short-Circuit Current
IOSS
VDVDD = 5.25V
Q150
mA
DIGITAL INTERRUPT (ERROR)
Interrupt Active Voltage
VINT
ISINK = 5.0mA
Interrupt Inactive Leakage
IINTZ
Interrupt Inactive Capacitance
CINTZ
Interrupt Short-Circuit Current
IINTSS
0.4
VDVDD 0.5
V
Q0.1
VDVDD = 2.7V
5
V
Q10
FA
0.4
V
Q1.0
FA
15
pF
30
mA
6 _______________________________________________________________________________________
Industrial Analog Current/
Voltage-Output Conditioners
(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for
the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
20
MHz
TIMING CHARACTERISTICS
Serial-Clock Frequency
fSCLK
(Note 4)
0
SCLK Pulse-Width High
tCH
40% duty cycle
20
ns
SCLK Pulse-Width Low
tCL
60% duty cycle
20
ns
CS_ Fall to SCLK Fall Setup Time
tCSS
To 1st SCLK falling edge
15
ns
SCLK Fall to CS_ Fall Hold Time
DIN to SCLK Fall Setup Time
tCSH
(Note 5)
0
ns
tDS
15
ns
DIN to SCLK Fall Hold Time
tDH
0
SCLK Fall to DOUT Settle Time
tDOT
CLOAD = 20pF
SCLK Fall to DOUT Hold Time
tDOH
CLOAD = 0pF
SCLK Fall to DOUT Disable
tDOZ
14th SCLK deassertion (Note 6)
SCLK Fall to READY Fall
tCR
CS_ Fall to DOUT Enable
tDOE
CS_ Rise to DOUT Disable
tCSDOZ
CS_ Rise to READY Rise
tCSR
CS_ Pulse-Width High
tCSW
ns
30
2
ns
ns
30
ns
16th SCLK assertion, CLOAD = 0pF or 20pF
2
30
ns
Asynchronous assertion
1
35
ns
Asynchronous deassertion
35
ns
Asynchronous deassertion, CLOAD = 20pF
35
ns
15
ns
Note 1: Use diodes as shown in the Typical Operating Circuit/Functional Diagram to ensure a voltage difference of 2V to 3.5V
from AVDD to AVDDO and from AVSS to AVSSO.
Note 2: RLOAD = 750I. For the MAX15500, RSENSE = 48.7I for FSMODE = DVDD and RSENSE = 42.2I for FSMODE = DGND.
For the MAX15501, RSENSE = 47.3I for FSMODE = DVDD and RSENSE = 41.2I for FSMODE = DGND. See the Typical
Operating Circuit/Functional Diagram.
Note 3: Condition at which part is stable.
Note 4: The maximum clock speed for daisy-chain applications is 10MHz.
Note 5: tCSH is applied to CS_ falling to determine the 1st SCLK falling edge in a free-running SCLK application. It is also applied
to CS_ rising with respect to the 15th SCLK falling edge to determine the end of the frame.
Note 6: After the 14th SCLK falling edge, the MAX15500/MAX15501 outputs are high impedance and DOUT data is ignored.
_______________________________________________________________________________________ 7
MAX15500/MAX15501
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output
mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)
2.5
4
IAVDD
0
-2
-4
-6
-8
2.0
1.5
1.0
0.5
IAVSS
-40 -25 -10 5 20 35 50 65 80 95 105
TEMPERATURE (NC)
20 35 50 65 80 95 105
TEMPERATURE (NC)
VOLTAGE-MODE OUTPUT NOISE
vs. FREQUENCY
700
MAX15500 toc04
1000
1.0
-40 -25 -10 5
20 35 50 65 80 95 105
TEMPERATURE (NC)
600
500
400
300
VAIN = 200mV
UNIPOLAR
CURRENT MODE
(0 to 20mA)
900
OUTPUT NOISE (FV/ Hz)
OUTPUT NOISE (FV/ Hz)
800
1.5
CURRENT-MODE OUTPUT NOISE
vs. FREQUENCY
VAIN = 0V
UNIPOLAR
VOLTAGE
MODE (0 to 5V)
900
2.0
0
-40 -25 -10 5
1000
2.5
0.5
0
10
RLOAD = 750I
CLOAD = 1FF
800
700
600
500
400
300
200
200
100
100
0
0
10
10k
100
1k
FREQUENCY (Hz)
10
10k
100
1k
FREQUENCY (Hz)
VOLTAGE-MODE PSRR
vs. SUPPLY VOLTAGE
DIGITAL FEEDTHROUGH
MAX15500 toc06
100
VAIN = 4.096V
90
80
MAX15500 toc07
2
3.0
MAX15500 toc05
6
NO LOAD
70
PSRR (FV/V)
SCLK
2V/div
VOUT (AC-COUPLED)
1mV/div
SCLK = DIN
SCLK = 1MHz
CS_ = HIGH
VAIN = 0.5 x VREFIN
400ns/div
MAX15500 toc03
3.0
OUTPUT SLEW RATE (mA/Fs)
NO LOAD
OUTPUT SLEW RATE (V/Fs)
8
MAX15500 toc01
10
CURRENT-MODE OUTPUT SLEW
RATE vs. TEMPERATURE
MAX15500 toc02
VOLTAGE-MODE OUTPUT SLEW
RATE vs. TEMPERATURE
SUPPLY CURRENT vs. TEMPERATURE
SUPPLY CURRENT (mA)
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
60
50
40
30
20
10
0
24
26
28
30
SUPPLY VOLTAGE (V)
32
8 _______________________________________________________________________________________
Industrial Analog Current/
Voltage-Output Conditioners
CURRENT-MODE PSRR vs.
SUPPLY VOLTAGE
LOAD TRANSIENT (VOLTAGE MODE)
MAX15500 toc09
MAX15500 toc08
1.0
0.9
0.8
PSRR (FA/V)
0.7
0.6
IOUT
10mA/div
OmA
VOUT (AC-COUPLED)
20mV/div
0.5
0.4
0.3
0.2
0.1
0
25
26 27 28 29 30
SUPPLY VOLTAGE (V)
31
32
40Fs/div
FULL-SCALE OUTPUT VOLTAGE
vs. TEMPERATURE
LOAD TRANSIENT (CURRENT MODE)
MAX15500 toc10
FULL-SCALE OUTPUT VOLTAGE (ppm/NC)
20
VOUT
10V/div
O
IOUT
10mA/div
0mA
VAIN = 4.096V
16
12
MAX15500 toc11
24
8
4
0
-4
-8
-12
-16
-20
-40 -25 -10 5 20 35 50 65 80 95
TEMPERATURE (NC)
40Fs/div
OUTPUT CURRENT DRIFT
vs. TEMPERATURE
1.5
SUPPLY CURRENT (mA)
6
2.0
2
-2
-6
MAX15500 toc13
VAIN = 4.096V
MAX15500 toc12
OUTPUT CURRENT DRIFT (ppm/NC)
10
STANDBY SUPPLY CURRENT
vs. TEMPERATURE
NO LOAD
1.0
0.5
IAVDD
0
-0.5
-1.0
IAVSS
-1.5
-10
-2.0
-40 -25 -10 5 20 35 50 65 80 95
TEMPERATURE (NC)
-40 -25 -10 5 20 35 50 65 80 95
TEMPERATURE (NC)
_______________________________________________________________________________________ 9
MAX15500/MAX15501
Typical Operating Characteristics (continued)
(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output
mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)
Typical Operating Characteristics (continued)
(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output
mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)
GAIN vs. FREQUENCY
(HART COMPLIANT)
WAKEUP FROM STANDBY
(CURRENT MODE)
MAX15500 toc15
0
OUTDIS
2V/div
0V
5V/div
VOUT
0V
IOUT
10mA/div
FULL-SCALE INPUT
BIPOLAR VOLTAGE MODE
5% OVERRANGE
BIPOLAR
CURRENT MODE
-4
GAIN (dB)
2V/div
OUTDIS
-8
-12
UNIPOLAR
CURRENT MODE
-16
VAIN = 40mVP-P
-20
10
50Fs/div
40Fs/div
SMALL-SIGNAL STEP RESPONSE
(CURRENT MODE)
SMALL-SIGNAL STEP RESPONSE
(VOLTAGE MODE)
MAX15500 toc17
100
1k
10k
FREQUENCY (Hz)
35.0
VAIN = 4.096V
34.5
SHORT-CIRCUIT CURRENT (mA)
VAIN
(AC-COUPLED)
50mV/div
VOUT
(AC-COUPLED)
100mV/div
IOUT
100FA/div
100k
OUTPUT SHORT-CIRCUIT CURRENT
vs. TEMPERATURE
MAX15500 toc18
VAIN
20mV/div
MAX15500 toc16
MAX15500 toc14
34.0
MAX15500 toc19
WAKEUP FROM STANDBY
(VOLTAGE MODE)
33.5
33.0
32.5
32.0
31.5
31.0
30.5
30.0
5Fs/div
1Fs/div
VOLTAGE-MODE MON TRANSFER
CURVE vs. OUTPUT CURRENT
CURRENT-MODE MON TRANSFER
CURVE vs. OUTPUT VOLTAGE
VAIN = 4.096V
NO LOAD ON MON
2.8
2.6
2.4
MON (V)
2.2
1.8
2.2
2.0
1.8
1.6
1.4
1.4
1.2
0
1
2
3
4
5
6 7
IOUT (mA)
8
9 10 11
VAIN = 4.096V
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
1.0
1.0
1.0
0
4
8
VOUT (V)
12
16
-40 -25 -10 5 20 35 50 65 80 95
TEMPERATURE (NC)
10 �������������������������������������������������������������������������������������
MAX15500 toc22
VOLTAGE-MODE MAXIMUM OUT TO
AVDDO VOLTAGE vs. TEMPERATURE
MAXIMUM INTERNAL VOLTAGE DROP (V)
2.6
3.0
-40 -25 -10 5 20 35 50 65 80 95
TEMPERATURE (NC)
MAX15500 toc21
VAIN = 4.096V
NO LOAD ON MON
MAX15500 toc20
3.0
MON (V)
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
Industrial Analog Current/
Voltage-Output Conditioners
LARGE-SIGNAL SETTLING TIME
(VOLTAGE MODE, RISING EDGE)
CURRENT-MODE OUTPUT
CONDUCTANCE vs. OUTPUT VOLTAGE
1.8
OUTPUT CONDUCTANCE (FA/V)
MAX15500 toc24
MAX15500 toc23
2.0
1.6
LARGE-SIGNAL SETTLING TIME
(VOLTAGE MODE, FALLING EDGE)
1.4
RL = 1kI
VAIN
5V/div
1.2
1.0
CL = 1nF, CCOMP = 0nF
MAX15500 toc25
VAIN
5V/div
VOUT
5V/div
CL = 47nF, CCOMP = 0nF
0.8
0
0.6
VOUT
5V/div
0.4
CL = 470nF, CCOMP = 4.7nF
CL = 470nF, CCOMP = 4.7nF
CL = 47nF, CCOMP = 0nF
0.2
CL = 1nF, CCOMP = 0nF
0
0
2
4
6
8
10 12
OUTPUT VOLTAGE (V)
14
16
LARGE-SIGNAL SETTLING TIME
(VOLTAGE MODE, RISING EDGE)
MAX15500 toc26
100Fs/div
100Fs/div
LARGE-SIGNAL SETTLING TIME
(VOLTAGE MODE, RISING EDGE)
LARGE-SIGNAL SETTLING TIME
(CURRENT MODE, RISING EDGE)
MAX15500 toc27
RL = 1kI
VAIN
5V/div
RL = 1kI
CL = 10FF,
CCOMP = 4.7nF
VOUT
5V/div
VOUT
CL = 100FF,
CCOMP = 4.7nF
CL = 100FF,
CCOMP = 4.7nF
LL = 1mH, CCOMP = 1nF
CL = 10FF,
CCOMP = 4.7nF
IOUT
4mA/div
10ms/div
LARGE-SIGNAL SETTLING TIME
(CURRENT MODE, FALLING EDGE)
200Fs/div
LARGE-SIGNAL SETTLING TIME
(CURRENT MODE, RISING EDGE)
LL = 22FH, CCOMP = 0nF
LL = 22FH, CCOMP = 0.15nF
RL = 20I
VAIN
LL = 220FH,
CCOMP = 0.47nF
LL = 220FH, CCOMP = 0nF
LL = 1mH, CCOMP = 1nF
LL = 1mH, CCOMP = 1nF
IOUT
4mA/div
IOUT
4mA/div
200Fs/div
MAX15500 toc31
RL = 20I
VAIN
5V/div
IOUT
4mA/div
LARGE-SIGNAL SETTLING TIME
(CURRENT MODE, FALLING EDGE)
MAX15500 toc30
MAX15500 toc29
RL = 750I
VAIN
5V/div
LL = 22FH, CCOMP = 0nF
LL = 220FH, CCOMP = 0nF
CL = 1FF, CCOMP = 4.7nF
10ms/div
RL = 750I
VAIN
5V/div
VAIN
5V/div
CL = 1FF, CCOMP = 4.7nF
MAX15500 toc28
RL = 1kI
20Fs/div
LL = 1mH, CCOMP = 1nF
LL = 220FH,
CCOMP = 0.47nF
LL = 22FH, CCOMP = 0.15nF
20Fs/div
______________________________________________________________________________________ 11
MAX15500/MAX15501
Typical Operating Characteristics (continued)
(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output
mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)
Typical Operating Characteristics (continued)
(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output
mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)
LARGE-SIGNAL SETTLING TIME
(CURRENT MODE, RISING EDGE)
MAX15500 toc32
LL = 50mH, CCOMP = 100nF
MAX15500 toc34
MAX15500 toc33
RL = 750I
RL = 20I
RL = 750I
VAIN
5V/div
LL = 80mH, CCOMP = 470nF
LL = 80mH, CCOMP = 470nF
LL = 50mH, CCOMP = 100nF
LL = 50mH, CCOMP = 100nF
LL = 10mH, CCOMP = 10nF
IOUT
4mA/div
100ms/div
LL = 80mH,
CCOMP = 470nF
IOUT
4mA/div
LL = 10mH, CCOMP = 10nF
IOUT
4mA/div
LL = 10mH, CCOMP = 10nF
VAIN
5V/div
10ms/div
100ms/div
LARGE-SIGNAL SETTLING TIME
(CURRENT MODE, FALLING EDGE)
CURRENT-MODE INL
MAX15500 toc35
VOLTAGE-MODE INL
RL = 20I
0.03
VAIN
20V/div
0.02
LL = 50mH, CCOMP = 100nF
LL = 10mH, CCOMP = 10nF
IOUT
4mA/div
0.01
0
0.02
0.01
0
-0.01
-0.01
-0.02
-0.02
-0.03
-0.03
-0.04
-0.04
0
10ms/div
0.03
INL (%FS)
LL = 80mH, CCOMP = 470nF
0.04
MAX15500 toc36
0.04
MAX15500 toc37
VAIN
5V/div
LARGE-SIGNAL SETTLING TIME
(CURRENT MODE, RISING EDGE)
LARGE-SIGNAL SETTLING TIME
(CURRENT MODE, FALLING EDGE)
INL (%FS)
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
0.6
1.2
1.8 2.4
VAIN (V)
3.0
3.6
4.2
0
1.2
1.8 2.4
VAIN (V)
CURRENT-MODE
OPEN-CIRCUIT DETECTION
VOLTAGE-MODE
SHORT-CIRCUIT DETECTION
MAX15500 toc39
MAX15500 toc38
IOUT
0mA
50mA/div
0.6
50mA/div
IOUT
0mA
ERROR
ERROR
2V/div
2V/div
100ms/div
100ms/div
12 �������������������������������������������������������������������������������������
3.0
3.6
4.2
Industrial Analog Current/
Voltage-Output Conditioners
PIN
NAME
1
SCLK
2
DIN
3
DOUT
SPI Data Output. Data transitions at DOUT on the falling edge of SCLK. DOUT is high impedance
when either CS1 or CS2 is high.
READY
Active-Low Device Ready Output. READY is an active-low output that goes low when the device
successfully completes processing an SPI data frame. READY returns high at the next rising edge
of CS_. In daisy-chain applications, the READY output typically drives the CS_ input of the next
device in the chain or a GPIO of a microcontroller.
5
ERROR
Active-Low Flag Output. ERROR is an open-drain output that pulls low when output short circuit,
output open circuit, overtemperature, or brownout conditions occur. ERROR typically drives an
interrupt input of a microcontroller. The ERROR output is cleared after the internal error register is
read through the SPI interface. Connect a 10kΩ pullup resistor from ERROR to DVDD.
6
DVDD
Digital Power-Supply Voltage Input. Apply either a 3V or 5V nominal voltage supply to DVDD.
DVDD powers the digital portion of the MAX15500/MAX15501. Bypass DVDD to DGND with a 0.1FF
capacitor as close as possible to the device.
Digital Ground
4
FUNCTION
SPI Clock Input. Activate SCLK only when CS_ is low to minimize noise coupling.
SPI Data Input. Data is clocked into the serial interface on the falling edge of SCLK.
7
DGND
8, 16,
24, 32
N.C.
9
OUTDIS
Active-Low Output Disable Input. OUTDIS is an active-low logic input that forces the analog output
to 0A or 0V and puts the device in standby mode when connected to DGND. Connect OUTDIS to
DVDD for normal operation.
10
FSSEL
Full-Scale Select Input. Connect FSSEL to DVDD for the MAX15500 when applying a +4.096V
reference at REFIN. Connect FSSEL to DGND for the MAX15501 when applying a +2.50V reference
at REFIN.
11
FSMODE
Overrange Mode Select Input. Connect FSMODE to DVDD to set the output voltage to 105%FS
when the input voltage is equal to the full-scale value. Connect FSMODE to DGND to set the output
voltage to 120%FS when the input voltage is equal to the full-scale value. FSMODE has no effect in
current mode.
12, 15, 27
AGND
Analog Ground
13
REFIN
Reference Voltage Input. Connect REFIN to an external +4.096V reference for the MAX15500 or
+2.5V reference for the MAX15501. REFIN is used to set the offset for unipolar and bipolar modes.
14
AIN
17
AVSSO
Negative Output Driver Supply Voltage Input. AVSSO provides power to the driver output stage.
Bypass AVSSO to AVSS with a 0.1FF capacitor. Use diodes as shown in the Typical Operating
Circuit/Functional Diagram to ensure a voltage difference of 2V to 3.5V between AVSS and AVSSO.
18
COMP
Output Amplifier Compensation Feedback Node. Connect a compensation capacitor from COMP to
OUT. See Table 10 for the recommended compensation capacitor values.
No Connection. Not internally connected.
Analog Signal Input. The analog input signal range at AIN is from 0V to the nominal full scale of
+4.096V for the MAX15500 and +2.5V for the MAX15501.
______________________________________________________________________________________ 13
MAX15500/MAX15501
Pin Description
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
Pin Description (continued)
PIN
NAME
FUNCTION
OUT
Analog Output. The analog voltage or current output range at OUT is programmable. See Tables
1 to 4 for possible output range settings.
20
AVDDO
Positive Output Driver Supply Voltage Input. AVDDO provides power to the driver output stage.
Bypass AVDDO to AVDD with a 0.1FF capacitor. Use diodes as shown in the Typical Operating
Circuit/Functional Diagram to ensure a voltage difference of 2V to 3.5V between AVDD and
AVDDO.
21
SENSERP
Sense Resistor Positive Connection. See the Typical Operating Circuit/Functional Diagram for the
typical connection.
22
SENSERN
Sense Resistor Negative Connection. See the Typical Operating Circuit/Functional Diagram for the
typical connection.
23
SENSEVN
Kelvin Sense Voltage Negative Input. See the Typical Operating Circuit/Functional Diagram for the
typical connection.
25
SENSEVP
Kelvin Sense Voltage Positive Input. See the Typical Operating Circuit/Functional Diagram for the
typical connection.
26
AVDD
Positive Analog Supply Voltage Input. Bypass AVDD to AGND with a 0.1FF capacitor.
28
AVSS
Negative Analog Supply Voltage Input. Bypass AVSS to AGND with a 0.1FF capacitor.
29
MON
Load Monitoring Output. MON provides an analog 0 to 3V output. See the Output Monitor section.
19
30
CS1
Active-Low SPI Chip-Select Input 1. See the SPI Interface section.
31
CS2
Active-Low SPI Chip-Select Input 2. See the SPI Interface section.
—
EP
Exposed Pad. Internally connected to AVSS. Connect to AVSS. Connect to a large copper area to
maximize thermal performance. Do not connect ground or signal lines through EP.
14 �������������������������������������������������������������������������������������
Industrial Analog Current/
Voltage-Output Conditioners
24V
5V
0.1FF
0.1FF
0.1FF
DVDD
DAC
AVDD
AVDDO
10kI
AIN
SENSEVP
CABLE1
SENSERP
PGA
2.5V/4.096V
REF
REFIN
COMP
OUT
10kI
CCOMP
RSENSE
CABLE2
SENSERN
RLOAD
SENSEVN
CLOAD
CABLE3
OFFSET
GENERATOR
OUTPUT STAGE
READ
INT
GPIO
SPI INTERFACE/
LOGIC I/O
ERROR
READY
FSSEL*
FC
POR
FSMODE
CS
DIN
SCLK
CS1
CS2
DOUT
DVDD
OUTDIS
WRITE
SCLK
MON
BROWNOUT
TEMP
MONITOR
AGND
DGND
ADC
MAX15500
MAX15501
AVSSO
AVSS
0.1FF
DVDD
0.1FF
-24V
*FSSEL IS CONNECTED TO DGND FOR THE MAX15501.
______________________________________________________________________________________ 15
MAX15500/MAX15501
Typical Operating Circuit/Functional Diagram
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
_Detailed Description
The MAX15500/MAX15501 output a programmable current up to Q24mA or a voltage up to Q12V proportional to
a control signal at AIN. The devices operate from a dual
15V to 32.5V supply. The control voltage applied at AIN
is typically supplied by an external DAC with an output
voltage range of 0 to 4.096V for the MAX15500 and 0
to 2.5V for the MAX15501. The MAX15500/MAX15501
are capable of both unipolar and bipolar current and
voltage outputs. In current mode, the devices produce
currents of -1.2mA to +24mA or -24mA to +24mA. In
voltage mode, the devices produce voltages of -0.3V
to +6V, -0.6V to +12V, or Q12V. To allow for overrange
and underrange capability in unipolar mode, the transfer
function of the MAX15500/MAX15501 is offset such that
when the voltage at AIN is 5% of full scale, IOUT is 0mA
and VOUT is 0V. Once VAIN attains full scale, VOUT or
IOUT becomes full scale +5% or +20% depending on
the state of FSMODE. The MAX15500/MAX15501 are
protected against overcurrent and short-circuit conditions when OUT goes to ground or a voltage up to
Q32.5V. The devices also monitor for overtemperature
and supply brownout conditions. The supply brownout
threshold is programmable between ±10V and ±24V in
2V increments.
device applications. The MAX15500/MAX15501 provide
extensive error reporting of short-circuit, open-circuit,
brownout, and overtemperature conditions through the
SPI interface and an additional open-drain interrupt
output (ERROR). The MAX15500/MAX15501 include an
analog 0 to 3V output (MON) to monitor the load condition at OUT.
Analog Section
The MAX15500/MAX15501 support two output modes:
current and voltage. Each mode has different full-scale
output values depending on the state of FSMODE as
detailed in Tables 1 to 4 and Figures 1 and 2. Use the
device configuration register in Table 6 to select the
desired voltage or current output range.
Startup
During startup, the MAX15500/MAX15501 output is set
to zero and all register bits are set to zero. The devices
remain in standby mode until they are configured
through the SPI interface.
Input Voltage Range
The MAX15500/MAX15501 are programmed through an
SPI interface with daisy-chain capability. A device ready
logic output (READY) and two device select inputs (CS1
and CS2) facilitate a daisy-chain arrangement for multiple
The input voltage full-scale level is selectable between
2.5V and 4.096V using logic input FSSEL. The MAX15500
is specified for a 0 to 4.096V input voltage range, while
the MAX15501 is specified for a 0 to 2.500V input voltage range. Connect FSSEL to DVDD to set the input
range to 0 to 4.096V for the MAX15500. Connect FSSEL
to DGND to set the input range to 0 to 2.500V for the
MAX15501.
Table 1. Output Values for FSMODE =
DVDD, Unipolar 5% Overrange
Table 3. Output Values for FSMODE =
DVDD, Bipolar 5% Overrange
OUTPUT RANGE
OUTPUT VALUES
VAIN = 5%FS
VAIN = FS
0 to 20mA
(4mA to 20mA)
0mA
21mA
0 to 5V
0V
5.25V
0 to 10V
0V
10.5V
Table 2. Output Values for FSMODE =
DGND, Unipolar 20% Overrange
OUTPUT RANGE
OUTPUT VALUES
VAIN = 5%FS
VAIN = FS
0 to 20mA
(4mA to 20mA)
0mA
24mA
0 to 5V
0V
6V
0 to 10V
0V
12V
OUTPUT RANGE
OUTPUT VALUES
VAIN = 0V
VAIN = FS
Q20mA
-21mA
+21mA
Q10V
-10.5V
+10.5V
Table 4. Output Values for FSMODE =
DGND, Bipolar 20% Overrange
OUTPUT RANGE
OUTPUT VALUES
VAIN = 0V
VAIN = FS
Q20mA
-24mA
+24mA
Q10V
-12V
+12V
16 �������������������������������������������������������������������������������������
Industrial Analog Current/
Voltage-Output Conditioners
In current mode, the MAX15500/MAX15501 program IOUT
and monitor the voltage at SENSERN.
VMON = 1.425V + (VSENSERN/20)
RLOAD = ((VMON - 1.425V) x 20)/IOUT(PROGRAMMED)
In voltage mode, the MAX15500/MAX15501 program
VOUT and monitor IOUT.
resets the ERROR pin but not the error register itself,
allowing the system to determine the source of the error
and take steps to fix the error condition. After the error
condition has been fixed, read the error register for the
second time to allow the device to clear the error register. Read the error register for the third time to verify
if the error register has been cleared. If another error
occurs after the first read, ERROR goes low again. More
information on reading and clearing the error register is
described in the SPI Interface section.
When an output short-circuit or output open-load error
occurs and disappears before the error register is read,
the intermittent bit is set in the error register. The intermittent bit does not assert for brownout and overtemperature error conditions.
VMON = 1.521V + 62.4 x ILOAD
Error Conditions
RLOAD = VOUT(PROGRAMMED)/((VMON - 1.521V)/62.4)
Error Handling
Many industrial control systems require error detection
and handling. The MAX15500/MAX15501 provide extensive error status reporting.
An open-drain interrupt flag output, ERROR, pulls low
when an error condition is detected. An error register
stores the error source. Reading the error register once
Output Short Circuit
The output short-circuit error bit asserts when the output
current exceeds 30mA (typ) for longer than 260ms. In
current mode, this error occurs when the sense resistor
is shorted and the sense voltage is not equal to 0V. In
voltage mode, this error occurs when the load is shorted
to the supply or ground. The short-circuit error activates
the intermittent bit in the error register if the error goes
away before the error register is read.
VOUT OR IOUT
VOUT OR IOUT
FS + 20%
FS
FS + 20%
FS
FS + 5%
FS + 5%
FSMODE = DGND
FSMODE = DGND
VAIN
50%FS
FSMODE = DVDD
FSMODE = DVDD
VAIN
5%FS
FS
-FS
-FS - 5%
-FS - 20%
FS
Figure 1. Unipolar Transfer Function
Figure 2. Bipolar Transfer Function
______________________________________________________________________________________ 17
MAX15500/MAX15501
Output Monitor
The MON output provides an analog voltage signal
proportional to the output voltage in current mode and
proportional to the output current in voltage mode. Use
this signal to measure the system load presented to the
output. The full-scale signal on MON is 3V with a typical
accuracy of 10%. The signal range is typically 1.5V to 3V
in unipolar mode and 0 to 3V in bipolar mode.
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
Output Open Load
The open-circuit error bit activates when VOUT is within
30mV of AVDDO or AVSSO and there is no short-circuit
current in current mode for longer than 260ms. This error
activates the intermittent bit in the error register if the
error goes away before the error register is read.
Internal Overtemperature
The MAX15500/MAX15501 enter standby mode if the die
temperature exceeds +150NC and the overtemperature
protection is enabled as shown in Table 6. When the die
temperature cools down below +140NC, the error register must be read back twice to resume normal operation.
The devices provide a 10NC hysteresis.
Brownout
The brownout-error bit activates when the supply voltage
(VAVDD or VAVSS) falls below the brownout threshold.
The threshold is programmable between Q10V to Q24V
in 2V steps. See Table 6 for details. The MAX15500/
MAX15501 provide a 2% hysteresis for the brownout
threshold. The accuracy of the threshold is typically
within 10%. During power-up, ERROR can go low and
the brownout register is set. Users need to read out the
error register twice to clear all the error register bits and
reset ERROR to high.
Output Protection
The MAX15500/MAX15501 supply inputs (AVDD, AVDDO,
AVSS, and AVSSO) and sense inputs (SENSERN,
SENSERP, SENSEVN, and SENSEVP) are protected
against voltages up to Q35V with respect to AGND. See
the Typical Operating Circuit/Functional Diagram for the
recommended supply-voltage connection.
SPI Interface
Standard SPI Implementation
The MAX15500/MAX15501 SPI interface supports daisychaining. Multiple MAX15500/MAX15501 devices can
be controlled from a single 4-wire SPI interface. The
MAX15500/MAX15501 feature dual CS_ inputs and
an added digital output, READY, that signals when
the devices finish processing the SPI frame. CS1 and
CS2 are internally OR-ed. Pull both CS1 and CS2 to
logic-low to activate the MAX15500/MAX15501. For a
daisy-chained application, connect the CS1 input of
all of the devices in the chain to the CS driver of the
microcontroller. Connect the CS2 input of the first device
to ground or to the CS driver of the microcontroller.
Connect CS2 of the remaining devices to the READY
output of the preceding device in the chain. The READY
output of the last device in the chain indicates when
all slave devices in the chain are configured. Connect
the READY output of the last device in the chain to the
microcontroller. Use the open-drain ERROR output as a
wired-OR interrupt. See Figures 3 to 6.
TO OTHER CHIPS/CHAINS
FC
RPULLUP
CSn
CS1
CS
SCLK
DWRITE
DREAD
INT
MONITOR
MAX15500
MAX15501
OPTIONAL CONNECTION
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
Figure 3. Single Connection (Compatible with Standard SPI)
18 �������������������������������������������������������������������������������������
Industrial Analog Current/
Voltage-Output Conditioners
FC
RPULLUP
CSn
CS1
CS
SCLK
DWRITE
DREAD
INT
MONITOR
MAX15500
MAX15501
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
OPTIONAL CONNECTION
Figure 4. Alternate Single Connection (Compatible with Standard SPI)
TO OTHER CHIPS/CHAINS
FC
RPULLUP
CSn
MAX15500
MAX15501
CS1
CS
SCLK
DWRITE
DREAD
INT
MONITOR
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
MAX15500
MAX15501
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
MAX15500
MAX15501
OPTIONAL CONNECTION
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
Figure 5. Daisy-Chain Connection (Compatible with Standard SPI)
______________________________________________________________________________________ 19
MAX15500/MAX15501
TO OTHER CHIPS/CHAINS
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
TO OTHER CHIPS/CHAINS
FC
RPULLUP
CSn
CS1
CS
SCLK
DWRITE
DREAD
INT
MAX15500
MAX15501
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
MAX15500
MAX15501
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
SPI DEVICE
CS
SCLK
DIN
DOUT
Figure 6. Daisy-Chain Terminating (Compatible with Standard SPI)
Modified SPI Interface Description
The SCLK, DIN, and DOUT of the MAX15500/MAX15501
assume standard SPI functionality. While the basic function of the MAX15500/MAX15501 CS_ inputs is similar
to the standard SPI interface protocol, the management
of the CS_ input within the chain is modified. When both
CS_ inputs are low, the MAX15500/MAX15501 assume
control of the DOUT line and continue to control the line
until the data frame is finished and READY goes low
(Figure 9). Once a complete frame is processed and the
READY signal is issued, the devices do not accept any
data from DIN, until either CS1 or CS2 rises and returns
low. A new communication cycle is initiated by a subsequent falling edge on CS1 or CS2. When either CS1
or CS2 is high, the MAX15500/MAX15501 SPI interface
deactivates, DOUT returns to a high-impedance mode,
READY (if active) clears, and any partial frames not yet
processed are ignored.
READY asserts once a valid frame is processed allowing
the next device in the chain to begin processing the subsequent frame. A valid frame consists of 16 SCLK cycles
following the falling edge of CS_. Once READY asserts,
it remains asserted until either CS_ rises, completing the
programming of the chain.
20 �������������������������������������������������������������������������������������
Industrial Analog Current/
Voltage-Output Conditioners
Single Device SPI Connection
For applications using a single MAX15500 or MAX15501,
connect both CS1 and CS2 inputs to the device-select
driver of the host microcontroller. Alternatively, connect
one of the CS_ inputs to the device-select driver of the
host microcontroller and the other CS_ to DGND. Both
methods allow standard SPI interface operation. See
Figures 3 and 4.
Daisy-Chain SPI Connection
The MAX15500/MAX15501-modified SPI interface allows
a single SPI master to drive multiple devices in a daisychained configuration, saving additional SPI channels for
other devices and saving cost in isolated applications.
Figure 5 shows multiple MAX15500/MAX15501 devices
connected in a daisy chain. The chain behaves as a
single device to the microcontroller in terms of timing
with an expanded instruction frame requiring 16 SCLK
cycles per device for complete programming. No timing
parameters are affected by the READY propagation as
all devices connect to the microcontroller chip-select
through the CS1 inputs.
A chain of MAX15500/MAX15501 devices can be terminated with any standard SPI-compatible single device
without a READY output. The MAX15500/MAX15501 portion of the chain continues to display timing parameters
comparable to a single device. See Figure 6.
When using the MAX15500/MAX15501 with mixed
chains, the connections could require some modification
to accommodate the interfaces of the additional devices
in the chain. Construct the daisy chain as shown in
Figure 7 when using devices with similar READY outputs
but without dual CS_ inputs such as the MAX5134 quad
16-bit DAC. The chain is subject to timing relaxation for
parameters given with respect to CS_ rising edges to
accommodate READY propagation to and through consecutive MAX5134 devices.
The chain can begin and terminate with either device
type. Each MAX5134 or MAX15500/MAX15501 device
in the chain could be replaced by a subchain of similar
devices. If the chain is terminated with a standard SPI
device, omit the optional connection from READY to the
monitor input on the microcontroller. The MAX15500/
MAX15501 portion of the chain continues to display timing parameters comparable to a single device.
SPI Digital Specifications and Waveforms
Figures 8, 9, and 10 show the operation of the modified
SPI interface. The minimum programming operation
typically used in single device applications is 16 SCLK
periods, the minimum for a valid frame. This cycle can
also represent the operation of the final device in a chain.
The extended programming operation is typically used
for devices in daisy-chained applications. In this case,
READY drives the chip-select input of the subsequent
device in the chain. The next device in the chain
begins its active frame on the 16th SCLK falling edge in
response to READY falling (latching DIN[13] on the 17th
SCLK falling edge, if present).
Aborted SPI Operations
Driving a CS_ input high before a valid SPI frame is
transmitted to the device can cause an erroneous command. Avoid driving CS_ high before a valid SPI frame is
transmitted to the device. See Figures 9 and 10 for valid
SPI operation timing.
SPI Operation Definitions
Input data bits DIN[13:11] represent the SPI command
address while DIN[9:0] represent the data written to
or read from the command address. The command
address directs subsequent input data to the proper
internal register for setting up the behavior of the device
and selects the correct status data for readback through
DOUT. Command address 0h points to a no-op command and does not impact the operation of the device.
DOUT is active during this operation and reads back
00h. Command address 1h points to the configuration
register used to program the MAX15500/MAX15501.
Device configuration takes effect following the 14th
SCLK falling edge. DOUT activates and remains low during this operation. Command addresses 4h and 5h point
to readback commands of the MAX15500/MAX15501.
Readback commands provide configuration and error
register status through DOUT[9:0] and do not affect the
internal operation of the device. Command addresses
2h, 3h, 6h, and 7h are reserved for future use. Table 5
shows the list of commands.
Device Configuration Operation
Table 6 shows the function of each bit written to the configuration register 1h. Table 7 shows the data readback
registers.
______________________________________________________________________________________ 21
MAX15500/MAX15501
The MAX15500/MAX15501 relinquish control of DOUT
once the devices process the frame(s). DOUT remains
high impedance when the SPI interface continues to hold
CS_ low beyond the required frame(s). Install a pullup/
puldown resistor at the DOUT line to maintain the desired
state when DOUT goes high impedance.
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
TO OTHER CHIPS/CHAINS
RPULLUP
FC
CSn
MAX15500
MAX15501
CS1
CS
SCLK
DWRITE
DREAD
INT
MONITOR
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
MAX15500
MAX15501
CS2
CS1
SCLK
DIN
DOUT
ERROR
READY
MAX5134
CS
SCLK
DIN
READY
OPTIONAL CONNECTION
Figure 7. Mixed MAX15500/MAX15501 and MAX5134 Daisy-Chain Connections
ERROR REGISTER UPDATED,
ERROR RE-EVALUATED
COMMAND EXECUTED
ACTIVE FRAME
DIN
X
DIN13 DIN12 DIN11 DIN10
DIN9
tDS
SCLK
tCSH
DOUT
1
2
tCSS
Z
3
4
DIN8
DIN7
DIN6
tCH
5
6
DIN5
DIN4
DIN3
DIN2
DIN1
DIN0
X
X
X
9
10
11
12
13
14
15
16
X
tCP
7
tCH
8
tCL
tDOH
tDOT
tDOZ
HIGH-Z
DOUT9 DOUT8 DOUT7 DOUT6 DOUT5 DOUT4 DOUT3 DOUT2 DOUT1 DOUT0
tDOE
CS_
tCSH
tCSW
Figure 8. Minimum SPI Programming Operation (Typically for Single Device Applications)
22 �������������������������������������������������������������������������������������
Industrial Analog Current/
Voltage-Output Conditioners
X
DIN13 DIN12 DIN11 DIN10
DIN9
tDS
SCLK
tCSH
DOUT
1
2
3
4
DIN8
DIN7
DIN6
tCH
5
6
tCSS
7
8
DIN4
DIN3
DIN2
DIN1
DIN0
X
X
9
10
11
12
13
14
15
16
tDOH
tCL
tCH
Z
DIN5
X
tCP
X
17
tDOZ
tDOT
HIGH-Z
DOUT9 DOUT8 DOUT7 DOUT6 DOUT5 DOUT4 DOUT3 DOUT2 DOUT1 DOUT0
tCSV
tDOE
CS_
tCR
tCSR
READY
Figure 9. Extended SPI Programming Operation (Daisy-Chained Applications)
ERROR REGISTER UPDATED,
ERROR RE-EVALUATED
SCLK
tCSH
DOUT
1
2
Z
4
5
6
7
8
9
10
11
12
13
14
15
16
X
HIGH-Z
DOUT9
tDOE
CS_
3
tCSS
tCSDOZ
OPERATION ABORTED
Figure 10. Aborted SPI Programming Operation (Invalid, Showing tCSDOZ and Internal Activity)
Readback Operations
Write to the command addresses 4h or 5h to read back the
configuration register data or the internal error information
through DOUT[9:0]. For error readback operations, each
bit corresponds to a specific error condition, with multiple
bits indicating multiple error conditions present.
Intermittent Errors
An intermittent error is defined as an error that is detected
and is resolved before the error register is read back.
When the error is resolved without intervention, the intermittent bit (bit 9) is set. The output short-circuit and output
open-load errors trigger the intermittent bit. Internal over-
temperature and supply voltage brownout do not trigger
the intermittent bit.
Error Reporting Applications
The ERROR output is typically connected to an interrupt input of the system microcontroller. The MAX15500/
MAX15501 only issue an interrupt when a new error condition is detected. The devices do not issue interrupts
when errors (either individual or multiple) are resolved
or when already reported errors persist. The system
microcontroller resets ERROR when the system microcontroller reads back the error register. ERROR does not
assert again unless a different error occurs.
______________________________________________________________________________________ 23
MAX15500/MAX15501
ACTIVE FRAME
DIN
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
Table 5. SPI Commands
COMMAND
ADDRESS
DIN[13:11]
NAME
DESCRIPTION
000
No-op
No operation.
001
Write configuration
Write device configuration register. See Table 6 for details.
010
Reserved
Reserved, no operation.
011
Reserved
Reserved, no operation.
100
Read error
Read error register status. See Table 7 for details.
101
Read configuration
Read device configuration register. See Table 6 for details.
110
Reserved
Reserved, no operation.
111
Reserved
Reserved, no operation.
Table 6. Configuration Register
LOCATION
DIN[9:7]
FUNCTION
Mode[2:0]
DIN[6:4]
VBOTH[2:0]
DIN[3]
Thermal
shutdown
DIN[10],
DIN[2:0]
—
DESCRIPTION
Sets device operating mode.
000 Mode[0]: Standby
001 Mode[1]: Bipolar current: Q20mA
010 Mode[2]: Unipolar current: 0 to 20mA
011 Mode[3]: Unipolar current: 4mA to 20mA
100 Mode[4]: Standby
101 Mode[5]: Bipolar voltage: Q10V
110 Mode[6]: Unipolar voltage: 0 to 10V
111 Mode[7]: Unipolar voltage: 0 to 5V
Sets supply voltage brownout threshold for error reporting.
000: Q10V
100: Q18V
001: Q12V
101: Q20V
010: Q14V
110: Q22V
011: Q16V
111: Q24V
0 = thermal protection off. 1 = thermal protection on.
Reserved
Note: Modes 2h and 3h are functionally identical.
Table 7. Readback Operations and Formatting
DOUT BITS
DESCRIPTION
COMMAND ADDRESS DIN[13:11] = 101. READBACK DEVICE CONFIGURATION REGISTER
DOUT[9:0]
See configuration register details in Table 6.
COMMAND ADDRESS DIN[13:11] = 100. READBACK ERROR REGISTER
DOUT[9]
Output intermittent fault. For details, see the Error Handling section.
DOUT[8]
Output short circuit. This bit asserts when IOUT > 30mA in voltage and current modes for longer than 260ms.
DOUT[7]
Output open load. This bit asserts when VOUT is within 30mV of AVDDO or AVSSO and there is no short-circuit
condition for longer than 260ms.
DOUT[6]
Internal overtemperature. This bit asserts when the die temperature exceeds +150NC.
DOUT[5]
Supply brownout. This bit asserts when either supply has entered the brownout limits. See Table 6 for details.
DOUT[4:0]
Reserved
24 �������������������������������������������������������������������������������������
Industrial Analog Current/
Voltage-Output Conditioners
1) Error resolved by the system.
a) The MAX15500/MAX15501 detect an error condition and ERROR asserts.
b) The host controller reads the error register for the
first time. This has the effect of resetting ERROR.
The data indicates to the host processor which
error is active.
c) The host processor resolves the error successfully.
d) The host processor reads the error register for the
second time. The data still shows that the error is
present as the error persisted for some time after
step b and before step c. If the error is either an
open load or short circuit, the intermittent bit is set.
An overtemperature or a brownout does not set the
intermittent bit. Reading the register a second time
resets the register.
e) The host reads the error register for a third time.
The data now shows the error is resolved and
future occurrences of this error will trigger ERROR
assertion.
2) Error resolved before the host processor reads error
register.
a) The MAX15500/MAX15501 detect an error condition and ERROR asserts, but the error resolves
itself.
b) The host controller reads the error register for the
first time resetting ERROR. The data indicates to
the host processor which error is active. The data
also indicates to the host that the error has been
resolved since the intermittent bit is set.
c) The host processor reads the error register for the
second time. The data still shows that the error is
active. If the error is for an output fault, the data
also indicates to the host that the error has been
resolved since the intermittent bit is set. Reading
the register a second time resets the register.
3) An error that cannot be resolved.
a) The MAX15500/MAX15501 detect an error condition and ERROR asserts.
b) The host controller reads the error register for the
first time and resets ERROR. The data indicates to
the host processor which error is active.
c) The host processor takes action to resolve the
error unsuccessfully.
d) The host processor reads the error register for the
second time. The data still shows that the error is
present.
e) The host processor reads the error for the third
time. The data show the error to be unresolved.
ERROR does not respond to the same error until
the error is resolved and reported. ERROR asserts
if different errors occur.
Applications Information
Setting the Output Gain in Current Mode
In current mode, there is approximately 1.0V across the
current-sensing resistors at full scale. The current sensing resistor sets the gain and is calculated as follows:
RSENSE = VSENSE_FS/IMAX
where VSENSE_FS is the full-scale voltage across the
sense resistor.
See Table 8 for values of VSENSE_FS.
Output Gain in Voltage Mode
The output gain in voltage mode is fixed as shown in
Table 9.
Selection of the Compensation
Capacitor (CCOMP)
Use Table 10 to select the compensation capacitor.
Layout Considerations
In the current-mode application, use Kelvin and a short
connection from SENSERN and SENSERP to the RSENSE
terminals to minimize gain-error drift. Balance and minimize all analog input traces for optimum performance.
______________________________________________________________________________________ 25
MAX15500/MAX15501
Since the MAX15500/MAX15501 do not use a continuous
clock signal, the SPI read cycles are used to cycle the
error detection and reporting logic. Continue to poll the
device until the error readback reports an all clear status
when resolving single or multiple errors. See below for
examples of typical error handling situations and the
effects of the SPI read operations.
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
Table 8. Recommended Current Setting Components
VREFIN
(V)
OVERRANGE
(%)
BIPOLAR/
UNIPOLAR
MODE
VSENSE_FS
(V)
RSENSE
(I)
IOUT
(mA)
IDEAL
GAIN
Unipolar
2
1.02144
42.2
24.205
0.2625/42.2
Bipolar
1
Q1.024
42.2
Q24.27
0.5/42.2
Unipolar
2
1.02144
48.7
20.97
0.2625/48.7
Bipolar
1
Q1.024
48.7
Q21.03
0.5/48.7
Unipolar
2
1.009375
41.2
24.5
0.425/41.2
Bipolar
1
Q1
41.2
Q24.27
0.8/41.2
Unipolar
2
1.009375
47.5
21.25
0.425/47.5
Bipolar
1
Q1
47.5
Q21.05
0.8/47.5
+20
4.096
+5
+20
2.500
+5
IDEAL TRANSFER
FUNCTION
IOUT = 0.2625 x (VAIN 0.05 x VREFIN)/42.2
IOUT = 0.5 x (VAIN - 0.5 x
VREFIN)/42.2
IOUT = 0.2625 x (VAIN 0.05 x VREFIN)/48.7
IOUT = 0.5 x (VAIN - 0.5 x
VREFIN)/48.7
IOUT = 0.425 x (VAIN 0.05 x VREFIN)/41.2
IOUT = 0.8 x (VAIN - 0.5 x
VREFIN)/41.2
IOUT = 0.425 x (VAIN 0.05 x VREFIN)/47.5
IOUT = 0.8 x (VAIN - 0.5 x
VREFIN)/47.5
Table 9. Full-Scale Output Voltages
VREFIN
(V)
OVERRANGE
(%)
+20
BIPOLAR/
UNIPOLAR
Unipolar
Bipolar
4.096
+5
Unipolar
Bipolar
+20
Unipolar
Bipolar
2.500
+5
Unipolar
Bipolar
MODE
IDEAL
GAIN
IDEAL
TRANSFER FUNCTION
7
1.5625
VOUT = 1.5625 x (VAIN - 0.05 x VREFIN)
6.08
6
3.125
VOUT = 3.125 x (VAIN - 0.05 x VREFIN)
12.16
5
6.0
7
1.375
VOUT = 1.375 x (VAIN - 0.05 x VREFIN)
5.3504
6
2.75
VOUT = 2.75 x (VAIN - 0.05 x VREFIN)
10.7008
5
5.25
VOUT = 5.25 x (VAIN - 0.5 x VREFIN)
Q10.752
7
2.5125
VOUT = 2.5125 x (VAIN - 0.05 x VREFIN)
5.96719
6
5.0625
VOUT = 5.0625 x (VAIN - 0.05 x VREFIN)
12.0234
5
9.6
7
2.175
VOUT = 2.175 x (VAIN - 0.05 x VREFIN)
5.16563
6
4.425
VOUT = 4.425 x (VAIN - 0.05 x VREFIN)
10.5094
5
8.4
VOUT = 6.0 x (VAIN - 0.5 x VREFIN)
VOUT = 9.6 x (VAIN - 0.5 x VREFIN)
VOUT = 8.4 x (VAIN - 0.5 x VREFIN)
26 �������������������������������������������������������������������������������������
IDEAL VOUT
(V)
Q12.288
Q12
Q10.5
Industrial Analog Current/
Voltage-Output Conditioners
MODE
CL (F)
RL (kI)
LL (H)
CCOMP (F)
Voltage
0 to 1n
1
0
0
Voltage
1n to 100n
1
0
1n
Voltage
100n to 1F
1
0
2.2n
Voltage
1F to 100F
1
0
4.7n
Current
0 to 1n
20 to 750
0 to 20F
0
Current
0 to 1n
20 to 750
20F to 1m
2.2n
Current
0 to 1n
20 to 750
1m to 50m
100n
Current
1n to 100n
20 to 750
0 to 20F
1n
Current
1n to 100n
20 to 750
20F to 1m
2.2n
Current
1n to 100n
20 to 750
1m to 50m
100n
Current
100n to 1F
20 to 750
0 to 20F
2.2n
Current
100n to 1F
20F to 1m
2.2n
Current
100n to 1F
20 to 750
20 to 750
1m to 50m
100n
Current
1F to 100F
20 to 750
0 to 20F
2.2n
Current
1F to 100F
20 to 750
20F to 1m
2.2n
Current
1F to 100F
20 to 750
1m to 50m
100n
CL = Load capacitance.
RL = Load resistance.
LL = Load inductance.
CCOMP = Compensation capacitance.
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
32 TQFN-EP
T3255+4
21-0140
90-0012
______________________________________________________________________________________ 27
MAX15500/MAX15501
Table 10. Recommended Compensation Capacitor for Various Load Conditions
MAX15500/MAX15501
Industrial Analog Current/
Voltage-Output Conditioners
Revision History
REVISION
NUMBER
REVISION
DATE
0
7/09
Initial release
—
1
2/11
Corrected description of DOUT pin in Pin Description section
13
DESCRIPTION
PAGES
CHANGED
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
28
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2011 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.