MAXIM MAX9950DCCB+

19-3014; Rev 2; 3/09
Dual Per-Pin Parametric Measurement Units
The MAX9949/MAX9950 dual parametric measurement
units (PMUs) feature a small package size, wide force
and measurement range, and high accuracy, making the
devices ideal for automatic test equipment (ATE) and
other instrumentation that requires a PMU per pin or per
site.
The MAX9949/MAX9950 force or measure voltages in
the -2V to +7V through -7V to +13V ranges, dependent
upon the supply voltage (VCC and VEE). The devices
handle supply voltages of up to +30V (VCC to VEE) and
a 20V device under test (DUT) voltage swing at full current. The MAX9949/MAX9950 also force or measure
currents up to ±25mA with a lowest full-scale range of
±2µA. Integrated support circuitry facilitates use of an
external buffer amplifier for current ranges greater than
±25mA.
A voltage proportional to the measured output voltage
or current is provided at the MSR_ output. Integrated
comparators, with externally set voltage thresholds, provide detection for both voltage and current levels. The
MSR_ and comparator outputs can be placed in a highZ state. Integrated voltage clamps limit the force output
to levels set externally. The force-current or the measure-current voltage can be offset -0.2V to +4.4V (IOS).
This feature allows for the centering of the control or
measured signal within the external DAC or ADC range.
The MAX9949D/MAX9950D feature an integrated 10kΩ
force-sense resistor between FORCE_ and SENSE_.
The MAX9949F/MAX9950F have no internal force-sense
resistor. These devices are available in a 64-pin 10mm x
10mm, 0.5mm pitch TQFP package with an exposed
8mm x 8mm die pad on the top (MAX9949) or the bottom
(MAX9950) of the package for efficient heat removal. The
exposed paddle is internally connected to V EE. The
MAX9949/MAX9950 are specified over the commercial
(0°C to +70°C) temperature range.
Applications
Features
o Force Voltage/Measure Current (FVMI)
o Force Current/Measure Voltage (FIMV)
o Force Voltage/Measure Voltage (FVMV)
o Force Current/Measure Current (FIMI)
o Force Nothing/Measure Voltage (FNMV)
o Five Programmable Current Ranges
±2µA
±20µA
±200µA
±2mA
±25mA
o -2V to +7V Through -7V to +13V Input Voltage
Range and Higher (Up to 20V Voltage Swing at
Full Current)
o Force-Current/Measure-Current Voltage Offset
(IOS)
o Programmable Voltage Clamps for the Force
Output
o Low-Leakage, High-Z Measure State
o 3-Wire Serial Interface
o Low Power, 8mA (max) per PMU
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX9949DCCB+
0°C to +70°C
64 TQFP-EPR*
MAX9949FCCB+
0°C to +70°C
64 TQFP-EPR*
MAX9950DCCB+
0°C to +70°C
64 TQFP-EP**
MAX9950FCCB+
0°C to +70°C
64 TQFP-EP**
+Denotes a lead(Pb)-free/RoHs-compliant part.
*EPR = Exposed pad on top.
**EP = Exposed pad on bottom.
Note: Exposed pad is internally connected to VEE.
Memory Testers
Selector Guide
VLSI Testers
System-on-a-Chip Testers
Structural Testers
Pin Configurations appear at end of data sheet.
PART
DESCRIPTION
MAX9949DCCB+
Internal 10kΩ force-sense resistor
MAX9949FCCB+
No internal force-sense resistor
MAX9950DCCB+
Internal 10kΩ force-sense resistor
MAX9950FCCB+
No internal force-sense resistor
________________________________________________________________ Maxim Integrated Products
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.
1
MAX9949/MAX9950
General Description
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
ABSOLUTE MAXIMUM RATINGS
VCC to AGND .......................................................................+20V
VEE to AGND.........................................................................-15V
VCC to VEE ...........................................................................+32V
VL to AGND............................................................................+6V
AGND to DGND.....................................................-0.5V to +0.5V
All Other Pins ...................................(VEE - 0.3V) to (VCC + 0.3V)
Digital Inputs/Outputs ...................................-0.3V to (VL + 0.3V)
Continuous Power Dissipation (TA = +70°C)
64-Pin TQFP-EP (derate 43.5mW/°C above +70°C)....3478mW
θJA (Note 1) ................................................................+23.0°C/W
θJC (Note 1) .....................................................................+8°C/W
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Operating Temperature (commercial) Range ........0°C to +70°C
Lead Temperature (soldering 10s) ..................................+300°C
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
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.
DC ELECTRICAL CHARACTERISTICS
(VCC = +12V, VEE = -7V, VL = +3.3V, TA = TMIN to TMAX, unless otherwise noted. TA < +25°C guaranteed by design and characterization.
Typical values are at TA = +25°C, unless otherwise specified.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
VCC 3.5V
V
FORCE VOLTAGE (Note 3)
Force Input Voltage Range
Forced Voltage
VIN0_,
VIN1_
VDUT
VEE +
3.5V
DUT current at full
scale
VCC = +12V, VEE = -7V
-2
+7
VCC = +18V, VEE = -
-7
+13
VEE +
3.5V
VCC 3.5V
DUT current = 0
Input Bias Current
Forced-Voltage Offset Error
±1
VFOS
TA = +25°C
-25
Forced-Voltage Offset
Temperature Coefficient
Forced-Voltage Gain Error
Forced-Voltage Linearity Error
µA
+25
±100
VFGE
TA = +25°C, nominal gain of +1
-1
Forced-Voltage Gain
Temperature Coefficient
0.005
TA = +25°C, gain and offset errors
calibrated out (Notes 4, 5)
IMOS
TA = +25°C (Note 4)
mV
µV/°C
+1
±10
VFLER
V
%
ppm/°C
-0.02
+0.02
%FSR
-1
+1
%FSR
MEASURE CURRENT (Note 3)
Measure-Current Offset
Measure-Current Offset
Temperature Coefficient
Measure-Current Gain Error
±20
IMGE
TA = +25°C (Note 7)
-1
Measure-Current Gain
Temperature Coefficient
Linearity Error
Measure Output Voltage Range
over Full Current Range (Note 8)
2
ppm/°C
+1
±20
IMLER
VMSR
TA = +25°C, gain, offset, and
common-mode errors
calibrated out (Notes 4, 5, 6)
Ranges A–D
%
ppm/°C
-0.02
+0.02
%FSR
-1
+1
nA
VIOS = VDUTGND
-4
+4
VIOS = 4V + VDUTGND
0
8
Range E
_______________________________________________________________________________________
V
Dual Per-Pin Parametric Measurement Units
(VCC = +12V, VEE = -7V, VL = +3.3V, TA = TMIN to TMAX, unless otherwise noted. TA < +25°C guaranteed by design and characterization.
Typical values are at TA = +25°C, unless otherwise specified.) (Note 2)
PARAMETER
Current-Sense Amp Offset
Voltage Input
Rejection of Output Measure
Error Due to Common-Mode
Sense Voltage
SYMBOL
VIOS
CMVRLER
Measure Current Range
CONDITIONS
MIN
Relative to VDUTGND
TYP
-0.2
Specified as the percent of full-scale range
change at the measure output per volt
change in the DUT voltage
0.001
MAX
UNITS
+4.4
V
0.007
%FSR/V
Range E, R_E = 1MΩ
-2
+2
Range D, R_D = 100kΩ
-20
+20
Range C, R_C = 10kΩ
-200
+200
Range B, R_B = 1kΩ
-2
+2
Range A, R_A = 80Ω
-25
+25
VIOS = VDUTGND
-4
+4
VIOS = 4V + VDUTGND
0
+8
+4.4
V
+1
%FSR
µA
mA
FORCE CURRENT (Note 3)
Input Voltage Range for Setting
Forced Current Over Full Range
VINI
Current-Sense Amp Offset
Voltage Input
VIOS
Relative to VDUTGND
-0.2
IFOS
TA = +25°C (Note 4)
-1
VIOS Input Bias Current
Forced-Current Offset
±1
Forced-Current Offset
Temperature Coefficient
Forced-Current Gain Error
TA = +25°C (Note 7)
-1
Forced-Current Gain
Temperature Coefficient
Forced-Current Linearity Error
Rejection of Output Error Due to
Common-Mode Load Voltage
µA
±20
IFGE
ppm/°C
+1
±20
IFLER
CMRIOER
TA = +25°C, gain, offset, and
common-mode errors
calibrated out (Notes 4, 5, 6)
Range E
%
ppm/°C
-0.02
+0.02
%FSR
-1
+1
nA
+0.007
%FSR/V
Specified as the percent of full-scale range
change of the forced current per volt
change in the DUT voltage
Range E, R_E = 1MΩ
Forced-Current Range
Ranges A–D
V
+0.001
-2
+2
Range D, R_D = 100kΩ
-20
+20
Range C, R_C = 10kΩ
-200
+200
Range B, R_B = 1kΩ
-2
+2
Range A, R_A = 80Ω
-25
+25
TA = +25°C
-25
+25
µA
mA
MEASURE VOLTAGE (Note 3)
Measure-Voltage Offset
VMOS
Measure-Voltage Offset
Temperature Coefficient
Gain Error
±100
VMGER
Measure-Voltage Gain
Temperature Coefficient
TA = +25°C, nominal gain of +1
-1
±0.005
±10
mV
µV/°C
+1
%
ppm/°C
_______________________________________________________________________________________
3
MAX9949/MAX9950
DC ELECTRICAL CHARACTERISTICS (continued)
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC = +12V, VEE = -7V, VL = +3.3V, TA = TMIN to TMAX, unless otherwise noted. TA < +25°C guaranteed by design and characterization.
Typical values are at TA = +25°C, unless otherwise specified.) (Note 2)
PARAMETER
Measure-Voltage Linearity Error
Measure Output Voltage Range
over Full DUT Voltage (VDUT)
SYMBOL
VMLER
VMSR
CONDITIONS
TA = +25°C, gain and offset errors
calibrated out (Notes 4, 5, 6)
DUT current at
full scale
VCC = +12V, VEE = -7V
VCC = +18V, VEE = -12V
DUT current = 0V
MIN
TYP
MAX
UNITS
-0.02
+0.02
%FSR
-2
+7
-7
+13
VEE +
3.5V
VCC 3.5V
V
FORCE OUTPUT
Off-State Leakage Current
Short-Circuit Current Limit
Force-to-Sense Resistor
-5
+5
ILIM-
TA = +25°C
-45
-28
ILIM+
+28
+45
RFS
D option only
7.8
10
nA
mA
13.3
kΩ
VEE +
3.5V
VCC 3.5V
V
-5
+5
nA
VEE +
3.5V
VCC 3.5V
V
+25
mV
SENSE INPUT
Input Voltage Range
Leakage Current
COMPARATOR INPUTS
Input Voltage Range
Offset Voltage
TA = +25°C
-25
±1
Input Bias Current
µA
VOLTAGE CLAMPS
Input Control Voltage
VCLLO_,
VCLHI_
Clamp Voltage Range
Clamp Voltage Accuracy
VEE +
3.4V
VCC 3.4V
V
VEE +
3.5V
VCC 3.5V
V
-100
+100
mV
DIGITAL INPUTS
Input High Voltage (Note 9)
Input Low Voltage (Note 9)
VIH
VIL
5V logic
+3.5
3.3V logic
+2.0
2.7V logic
+1.7
V
5V and 3.3V logic
+0.8
2.5V logic
+0.7
V
Input Current
IIN
±1
µA
Input Capacitance
CIN
3.0
pF
COMPARATOR OUTPUTS (Note 9)
Output High Voltage
VOH
VL = +2.375V to +5.5V, RPUP = 1kΩ
Output Low Voltage
VOL
VL = +2.375V to +5.5V, RPUP = 1kΩ
VL - 0.2
V
+0.4
V
High-Z State Leakage Current
±1
µA
High-Z State Output Capacitance
6.0
pF
4
_______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
(VCC = +12V, VEE = -7V, VL = +3.3V, TA = TMIN to TMAX, unless otherwise noted. TA < +25°C guaranteed by design and characterization.
Typical values are at TA = +25°C, unless otherwise specified.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
Output High Voltage
VOH
IOUT = 1mA, VL = +2.375V to +5.5V, relative
to DGND
VL 0.25
Output Low Voltage
VOL
IOUT = -1mA, VL = +2.375V to +5.5V,
relative to DGND
Positive Supply
VCC
(Note 2)
+10
+12
+18
Negative Supply
VEE
(Note 2)
-15
-7
-5
UNITS
DIGITAL OUTPUTS (Note 9)
V
0.2
V
POWER SUPPLY
Total Supply Voltage
VCC - VEE
Logic Supply
VL
Positive Supply Current
ICC
Negative Supply Current
IEE
Logic Supply Current
IL
V
+30
V
+5.5
V
No load, clamps enabled
16.0
mA
No load, clamps enabled
16.0
mA
No load, all digital inputs at rails
1.2
mA
+2.375
Analog Ground Current
IAGND
No load, clamps enabled
0.9
mA
Digital Ground Current
IDGND
No load, all digital inputs at rails
1.4
mA
Power-Supply Rejection Ratio
PSRR
1MHz, measured at force output
20
60Hz, measured at force output
85
dB
AC ELECTRICAL CHARACTERISTICS
(VCC = +12V, VEE = -7V, VL = +3.3V, CCM = 120pF, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. TA < +25°C guaranteed
by design and characterization. Typical values are at TA = +25°C, unless otherwise specified.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
30
µs
FORCE VOLTAGE (Notes 10, 11)
Settling Time
Range E, R_E = 1MΩ
160
Range D, R_D = 100kΩ
35
Range C, R_C = 10kΩ
25
Range B, R_B = 1kΩ
20
Range A, R_A = 80Ω
25
Maximum Stable Load
Capacitance
2500
pF
FORCE VOLTAGE/MEASURE CURRENT (Notes 10, 11)
Settling Time
Range Change Switching
Range E, R_E = 1MΩ
480
Range D, R_D = 100kΩ
50
Range C, R_C = 10kΩ
35
Range B, R_B = 1kΩ
20
Range A, R_A = 80Ω
25
In addition to force-voltage and measurecurrent settling times, range A to range B,
R_A = 80Ω, R_B = 1kΩ
10
45
µs
µs
_______________________________________________________________________________________
5
MAX9949/MAX9950
DC ELECTRICAL CHARACTERISTICS (continued)
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
AC ELECTRICAL CHARACTERISTICS (continued)
(VCC = +12V, VEE = -7V, VL = +3.3V, CCM = 120pF, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. TA < +25°C guaranteed
by design and characterization. Typical values are at TA = +25°C, unless otherwise specified.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
45
µs
50
µs
FORCE CURRENT (Notes 10, 11)
Settling Time
Range E, R_E = 1MΩ
300
Range D, R_D = 100kΩ
100
Range C, R_C = 10kΩ
40
Range B, R_B = 1kΩ
25
Range A, R_A = 80Ω
25
FORCE CURRENT/MEASURE VOLTAGE (Notes 10, 11, 12)
Range E, R_E = 1MΩ
1600
Range D, R_D = 100kΩ
170
Range C, R_C = 10kΩ
40
Range B, R_B = 1kΩ
25
Range A, R_A = 80Ω
25
In addition to force-voltage and measurecurrent settling times, range A to range B,
R_A = 80Ω, R_B = 1kΩ
12
µs
CLMSR = 100pF
0.2
µs
HIZ_ or HIZMSR True (0) to
High-Z
CLMSR = 100pF, measured from 50% of
digital input voltage to 10% of output
voltage
250
ns
HIZ_ or HIZMSR False (1) to
Active
CLMSR = 100pF, measured from 50% of
digital input voltage to 90% of output
voltage
5
µs
Settling Time
Range Change Switching
SENSE INPUT TO MEASURE OUTPUT PATH (Note 12)
Settling Time
MEASURE OUTPUT
Maximum Stable Load
Capacitance
1000
pF
FORCE OUTPUT
HIZFORCE True (0) to High-Z
Measured from 50% of digital input voltage
to 10% of output voltage
2
µs
HIZFORCE False (1) to Active
Measured from 50% of digital input voltage
to 90% of output voltage
2
µs
Propagation Delay
50mV overdrive, 1VP-P, CLCOMP = 20pF,
RPUP = 1kΩ measured from input-threshold
zero crossing to 50% of output voltage
(Note 13)
75
ns
Rise Time
CLCOMP = 20pF, RPUP = 1kΩ measured
from input-threshold zero crossing to 50%
of output voltage
60
ns
Fall Time
CLCOMP = 20pF, RPUP = 1kΩ, 20% to 80%
5
ns
COMPARATORS
6
_______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
(VCC = +12V, VEE = -7V, VL = +3.3V, CCM = 120pF, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. TA < +25°C guaranteed
by design and characterization. Typical values are at TA = +25°C, unless otherwise specified.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DISABLE True (0) to High-Z
CLCOMP = 20pF, measured from 50% of
digital input voltage to 10% of output
voltage
300
ns
DISABLE False (1) to Active
CLCOMP = 20pF, measured from 50% of
digital input voltage to 90% of output
voltage
100
ns
SERIAL PORT (VL = +3.0V, CDOUT = 10pF)
Serial Clock Frequency
fSCLK
20
SCLK Pulse-Width High
tCH
12
SCLK Pulse-Width Low
tCL
12
SCLK Fall to DOUT Valid
tDO
MHz
ns
ns
22
ns
CS Low to SCLK High Setup
tCSS0
10
SCLK High to CS High Hold
tCSH1
22
ns
SCLK High to CS Low Hold
tCSH0
0
ns
CS High to SCLK High Setup
ns
ns
tCSS1
5
DIN to SCLK High Setup
tDS
10
ns
DIN to SCLK High Hold
tDH
0
ns
(Note 14)
CS Pulse-Width High
tCSWH
10
ns
CS Pulse-Width Low
tCSWL
10
ns
LOAD Pulse-Width Low
tLDW
20
ns
VDD High to CS Low (Power-Up)
(Note 14)
500
µs
Note 2: The device operates properly with different supply voltages with equally different voltage swings.
Note 3: Tested at VCC = +18V and VEE = -12V.
Note 4: Interpret errors expressed in terms of %FSR (percent of full-scale range) as a percentage of the end-point to end-point
range, i.e., for the ±25mA range, the full-scale range = 50mA and a 1% error = 500µA.
Note 5: Case must be maintained ±5°C for linearity specifications.
Note 6: Current linearity specifications are maintained to within 700mV of the clamp voltages when the clamps are enabled.
Note 7: Tested in range C.
Note 8: Linearity of the measured output is only guaranteed within the specified current range.
Note 9: The digital interface accepts +5V, +3.3V, and +2.5V CMOS logic levels. The voltage at VL adjusts the threshold.
Note 10: Settling times are to 0.1% of FSR. Cx = 47pF.
Note 11: All settling times are specified using a single compensation capacitor (Cx) across all current-sense resistors. Use an individual capacitor across each sense resistor for better performance across all current ranges, particularly the lower ranges.
Note 12: The actual settling time of the measured voltage path (SENSE_ input to MSR_ output) is less than 1µs. However, the R-C
time constant of the sense resistor and the load capacitance causes a longer overall settling time of the DUT voltage. This
settling time is a function of the current-range resistor used.
Note 13: The propagation delay time is only guaranteed over the force-voltage output range. Propagation delay is measured by
holding the SENSE_ input voltage steady and transitioning THMAX_ or THMIN_.
Note 14: Guaranteed by design.
_______________________________________________________________________________________
7
MAX9949/MAX9950
AC ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(VCC = +12V, VEE = -7V, CL = 100pF, RL to +2.5V, range A: R_A = 80Ω, RL = 180Ω; range B: R_B = 1kΩ, RL = 2.25kΩ; range C: R_C =
10kΩ, RL = 22.5kΩ; range D: R_D = 100kΩ, RL = 225kΩ; range E: R_E = 1MΩ, RL = 2.25MΩ, TA = +25°C.
MAX9949/50 toc01
FORCE_
5V/div
0
MAX9949/50 toc03
MAX9949/50 toc02
IN_
5V/div
0
TRANSIENT RESPONSE FVMI MODE
RANGE E
TRANSIENT RESPONSE FVMI MODE
RANGE D
TRANSIENT RESPONSE FVMI MODE
RANGES A, B, C
IN_
5V/div
0
0
IN_
5V/div
0
FORCE_
5V/div
FORCE_
5V/div
0
20µs/div
100µs/div
1.0ms/div
TRANSIENT RESPONSE FVMV MODE
RANGE C
TRANSIENT RESPONSE FIMI MODE
RANGES A, B, C
TRANSIENT RESPONSE FIMI MODE
RANGE D
MAX9949/50 toc04
MAX9949/50 toc06
MAX9949/50 toc05
0
IN_
5V/div
0
MSR_
5V/div
IN_
5V/div
0
20µs/div
IN_
5V/div
0
FORCE_
5V/div
0
FORCE_
5V/div
0
100µs/div
20µs/div
TRANSIENT RESPONSE FIMI MODE
RANGE E
IOS vs. POWER SUPPLIES
MAX9949/50 toc07
MAX9949/50 toc08
20
VCC
15
IN_
5V/div
0
FORCE_
5V/div
0
VOLTAGE (V)
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
11.2
10
4.4
5
0
3.2
IOS (MAX)
IOS (MIN)
1.8
-0.2
-5
-10
VEE
-7
-15
1.0ms/div
8
_______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
PIN
NAME
FUNCTION
MAX9950
MAX9949
1, 16,
33, 48
1, 16,
33, 48
VEE
Negative Analog Supply Input
2, 15,
34, 47
2, 15,
34, 47
VCC
Positive Analog Supply Input
3
14
RBCOM
4
13
RBE
PMU-B Range E Resistor Connection
5
12
RBD
PMU-B Range D Resistor Connection
6
11
RBC
PMU-B Range C Resistor Connection
7
10
RBB
PMU-B Range B Resistor Connection
8
9
RBA
PMU-B Range A Resistor Connection
9
8
FORCEB PMU-B Driver Output. Forces a current or voltage to the DUT for PMU-B.
10
7
SENSEB
PMU-B Sense Input. A Kelvin connection to the DUT. Provides the feedback signal in FVMI
mode and the measured signal in FIMV mode for PMU-B.
11
6
CC1B
PMU-B Compensation Capacitor Connection 1. Provides compensation for the PMU-B main
amplifier.
12
5
CC2B
PMU-B Compensation Capacitor Connection 2. Provides compensation for the PMU-B main
amplifier.
13
4
RXDB
PMU-B Current-Range Sense-Resistor Connection. Connects to the external current-range
sense resistor on the DUT side for PMU-B. See Figure 5.
14
3
RXAB
PMU-B Current-Range Sense-Resistor Connection. Connects to the external current-range
sense resistor on the amplifier side for PMU-B. See Figure 5.
17
64
CS
18
63
LOAD
19
62
SCLK
20
61
DIN
21
60
DUTHB
PMU-B Window-Comparator High-Comparator Output. A sense-B voltage above the VTHMAXB
level forces the DUTHB output low. DUTHB is an open-drain output.
22
59
DUTLB
PMU-B Window-Comparator Low-Comparator Output. A sense-B voltage below the VTHMINB
level forces the DUTLB output low. DUTLB is an open-drain output.
PMU-B Range-Setting-Resistor Common Connection. Connect to one end of all the rangesetting resistors (RB_) for PMU-B. Also serves as the input to an external current-range buffer
for PMU-B.
Chip-Select Input. Force CS low to enable communication with the serial port.
Serial Port Load Input. A logic low asynchronously loads data from the input registers into the
PMU registers.
Serial Clock Input
Serial Data Input. Data loads into DIN MSB first.
23
58
24, 27
54, 57
EXTBSEL PMU-B External Current-Range Selector. Selects the external current range for PMU-B.
DGND
Digital Ground
25
56
DOUT
Serial Data Output. Provides data out from the shift register. Facilitates daisy-chaining to DIN
of a downstream PMU. DOUT clocks out data MSB first.
26
55
VL
28
53
29
52
Logic Supply Voltage Input. The voltage applied at VL sets the upper logic-voltage level.
EXTASEL PMU-A External Current-Range Selector. Selects the external current range for PMU-A.
DUTLA
PMU-A Window-Comparator Low-Comparator Output. A sense-A voltage below the VTHMINA
level forces the DUTLA output low. DUTLA is an open-drain output.
_______________________________________________________________________________________
9
MAX9949/MAX9950
Pin Description
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
Pin Description (continued)
PIN
NAME
FUNCTION
51
DUTHA
PMU-A Window-Comparator High-Comparator Output. A sense-A voltage above the VTHMAXA
level forces the DUTHA output low. DUTHA is an open-drain output.
31
50
HI-ZB
PMU-B MSRB Output State Control. A logic low places the MSRB output in a high-impedance
state.
32
49
HI-ZA
PMU-A MSRA Output State Control. A logic low places the MSRA output in a high-impedance
state.
35
46
RXAA
PMU-A Current-Range Sense-Resistor Connection. Connects to the external current-range
sense resistor on the amplifier side for PMU-A. See Figure 5.
36
45
RXDA
PMU-A Current-Range Sense-Resistor Connection. Connects to the external current-range
sense resistor on the DUT side for PMU-A. See Figure 5.
37
44
CC2A
PMU-A Compensation Capacitor Connection 2. Provides compensation for the PMU-A main
amplifier.
38
43
CC1A
PMU-A Compensation Capacitor Connection 1. Provides compensation for the PMU-A main
amplifier.
39
42
SENSEA
PMU-A Sense Input. A Kelvin connection to the DUT. Provides the feedback signal in FVMI
mode and the measured signal in FIMV mode for PMU-A.
40
41
FORCEA PMU-A Driver Output. Forces a current or voltage to the DUT for PMU-A.
41
40
RAA
PMU-A Range A Resistor Connection
42
39
RAB
PMU-A Range B Resistor Connection
43
38
RAC
PMU-A Range C Resistor Connection
44
37
RAD
PMU-A Range D Resistor Connection
45
36
RAE
PMU-A Range E Resistor Connection
46
35
RACOM
PMU-A Range-Setting-Resistor Common Connection. Connect to one end of all range-setting
resistors (RA_) for PMU-A. Also serves as the input to an external current range buffer for
PMU-A.
49
32
THMAXA
PMU-A Window-Comparator Upper Threshold Voltage Input. Sets the upper voltage threshold
for the PMU-A window comparator.
50
31
THMINA
PMU-A Window-Comparator Lower Threshold Voltage Input. Sets the lower voltage threshold
for the PMU-A window comparator.
MAX9950
MAX9949
30
10
51
30
CLHIA
PMU-A Upper Clamp Voltage Input. Sets the upper clamp voltage level for PMU-A.
52
29
CLLOA
PMU-A Lower Clamp Voltage Input. Sets the lower clamp voltage level for PMU-A.
53
28
IN0A
Input Voltage 0 for PMU-A. Sets the forced current in FI mode or the forced voltage in FV
mode for PMU-A.
54
27
IN1A
Input Voltage 1 for PMU-A. Sets the forced voltage in FV mode or the forced current in FI
mode for PMU-A.
55
26
MSRA
PMU-A Measurement Output. Provides a voltage equal to the SENSE voltage in FIMV mode
and provides a voltage proportional to the DUT current in FVMI mode for PMU-A. Force HI-ZA
low to place MSRA in a high-impedance state.
56
25
IOS
Offset Voltage Input. Sets an offset voltage for the internal current-sense amplifier for both
PMU-A and -B.
______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
PIN
NAME
FUNCTION
MAX9950
MAX9949
57
24
AGND
Analog Ground
58
23
MSRB
PMU-B Measurement Output. Provides a voltage equal to the SENSE voltage in FIMV mode
and provides a voltage proportional to the DUT current in FVMI mode for PMU-B. Force HI-ZB
low to place MSRB in a high-impedance state.
59
22
IN1B
Input Voltage 1 for PMU-B. Sets the forced voltage in FV mode or the forced current in FI
mode for PMU-B.
60
21
IN0B
Input Voltage 0 for PMU-B. Sets the forced current in FI mode or the forced voltage in FI mode
for PMU-B.
61
20
CLLOB
PMU-B Lower-Clamp Voltage Input. Sets the lower clamp voltage level for PMU-B.
62
19
CLHIB
PMU-B Upper-Clamp Voltage Input. Sets the upper clamp voltage level for PMU-B.
63
18
THMINB
PMU-B Window-Comparator Lower Threshold Voltage Input. Sets the lower voltage threshold
for the PMU-B window comparator.
64
17
THMAXB
PMU-B Window-Comparator Upper Threshold Voltage Input. Sets the upper voltage threshold
for the PMU-B window comparator.
Detailed Description
The MAX9949/MAX9950 force or measure voltages in
the -2V to +7V through -7V to +13V ranges, dependent
upon the supply voltage range (V CC and V EE ).
However, the devices can handle supply voltages up to
+30V (VCC to VEE) and a 20V DUT voltage swing at full
current. The MAX9949/MAX9950 PMU also force or
measure currents up to ±25mA, with a lowest full-scale
range of ±2µA. Use an external buffer amplifier for current ranges greater than ±25mA.
The MSR_ output presents a voltage proportional to the
measured voltage or current. Place MSR_ in a low-leakage, high-impedance state by pulling HI-Z_ low.
Integrated comparators with externally programmable
voltage thresholds provide “too low” (DUTL_) and “too
high” (DUTH_) voltage-monitoring outputs. Each comparator output features a selectable high-impedance
state. The devices feature separate FORCE_ and
SENSE_ connections and are fully protected against
short circuits. The FORCE_ output has two voltage
clamps, negative (CLLO_) and positive (CLHI_), to limit
the voltage to externally provided levels. Two control
voltage inputs, selected independently of the PMU
mode, allow for greater flexibility.
Serial Interface
The MAX9949/MAX9950 use a standard 3-wire
SPI™/QSPI™/MICROWIRE™-compatible serial port.
Once the input data register fills, the data becomes available at DOUT MSB first. This data output allows for
daisy-chaining multiple devices. Figures 1, 2, and 3
show the serial interface timing diagrams.
Serial Port Speed
The serial port timing specifications are measured at a
logic supply voltage (VL) of +3.0V, ensuring operation
of the serial port at rated speed for VL from +3.0V to
+5.5V.
The serial interface has two ranks. Each PMU has an
input register that loads from the serial port shift register.
Each PMU also has a PMU register that loads from the
input register. Data does not affect the PMU until it reaches the PMU register. This register configuration permits
loading of the PMU data into the input register at one time
and then latching the input register data into the PMU
register later, at which time the PMU function changes
accordingly. The register configuration also provides the
ability to change the state of the PMU asynchronously
with respect to the loading of that PMU’s data into the serial port. Thus, the PMU easily updates simultaneously with
other PMUs or other devices.
Use the LOAD input to asynchronously load all input
registers into the PMU registers. If LOAD remains low
when data latches into an input register, the data also
transfers to the PMU register.
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor, Corp.
______________________________________________________________________________________
11
MAX9949/MAX9950
Pin Description (continued)
Dual Per-Pin Parametric Measurement Units
MAX9949/MAX9950
Functional Diagram
TO EXTERNAL CURRENT BOOSTER
FOR HIGHEST RANGE
RXA_
RXD_
CX
RE
RD
EXTSEL_
VEE
VCC
IN1_
RB
CCM
RA
CC2_
CLLO_
CC1_
CLHI_
RC
R_COM
R_A
R_B
R_C
R_D
R_E
1
RANGE RESISTOR SELECT
FORCE_
0
HI-ZFORCE_
IN0_
INMODE_
IOS
CLENABLE_
RS0_
CS
RS1_
SCLK
RS2_
LOAD
DIN
SERIAL
INTERFACE
1
10
TO OTHER PMU CHANNEL
0
FMODE_
DOUT
VL
MMODE_
HI-Z_
RFS*
HI-ZMEAS_
0
MSR_
1
SENSE_
DISABLE_
THMAX_
DUTH_
MAX9949
MAX9950
DUTL_
THMIN_
AGND
DGND
*RFS INTERNAL TO MAX9949D/MAX9950D ONLY
12
______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
MAX9949/MAX9950
CS
INPUT
REGISTER(S)
UPDATED
SCLK
DIN
D15
DOUT
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Q15
Q14
Q13
Q12
Q11
Q10
Q9
Q8
Q7
Q6
Q5
Q4
Q3
Q2
Q1
Q0
LAST BIT FROM
PREVIOUS WRITE
FIRST BIT FROM
PREVIOUS WRITE
LOAD
PMU REGISTERS
UPDATED
Figure 1. Serial Port Timing with Asynchronous Load
CS
INPUT AND PMU
REGISTER(S)
UPDATED
SCLK
DIN
D15
DOUT
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Q15
Q14
Q13
Q12
Q11
Q10
Q9
Q8
Q7
Q6
Q5
Q4
Q3
Q2
Q1
FIRST BIT FROM
PREVIOUS WRITE
Q0
LAST BIT FROM
PREVIOUS WRITE
LOAD
LOAD = 0
Figure 2. Serial Port Timing with Synchronous Load
______________________________________________________________________________________
13
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
tCH
SCLK
tCL
tCSSO
tCSS1
tCSH1
tCSHO
CS
tCSWH
tDH
tDS
DIN
D15
DOUT
D14
D15last
D14last
D13
D12
D11
D10
D1
D13last
D12last
D11last
D10last
D1last
D0
D0last
tDO
tLDW
LOAD
Figure 3. Detailed Serial Port Timing Diagram
CS
SCLK
DIN
SHIFT REGISTER /16
6
CONTROL
DECODE
10
INPUT REGISTER A
10
LOAD
DOUT
INPUT REGISTER B
10
PMU REGISTER A
PMU REGISTER B
TO PMUA
TO PMUB
Figure 4. Dual PMU Serial Port Block Diagram
14
______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
BIT
15 (MSB)
Table 2. Address Bit
BIT NAME
INMODE
(BIT 3)
A2
(BIT 2)
A1
14
FMODE
0
0
Do not update any input register (NOP).
13
MMODE
0
1
Only update input register A.
12
RS2
1
0
Only update input register B.
11
RS1
10
RS0
1
1
Update both input registers with the same
data.
9
CLENABLE
8
HI-ZFORCE
7
HI-ZMSR
6
DISABLE
5
OPERATION
Table 3. Control Bit
Don’t care
(BIT 1)
C2
0
(BIT 0)
C1
0
4
Don’t care
0
1
3
A2
Transfer PMU-A input register to PMU
register.
1
0
Transfer PMU-B input register to PMU
register.
1
1
Transfer both input registers to the PMU
registers.
2
A1
1
C2
0 (LSB)
C1
Bit Order
The MAX9949/MAX9950 use the bit order, MSB first in
and first out, as shown in Table 1.
PMU Control
Programming both PMUs with the same data requires a
16-bit word. Programming each PMU with separate
data requires two 16-bit words.
The address bits specify which input registers the shift
register loads. Table 2 describes the function of the
address bits.
Bits (C2, C1) specify how the data loads into the second
rank PMU registers. These two control bits serve a similar
function as the LOAD input. The specified actions occur
when CS goes high, whereas the LOAD input loads the
PMU register anytime. When either C2 or C1 is low, the
corresponding PMU register is transparent. Table 3
describes the function of the two control bits.
The NOP operation requires A1 = A2 = C1 = C2 = 0. In
this case, the data transfers through the shift register
without changing the state of the MAX9949/MAX9950.
C1 = C2 = 0 allows for data transfer from the shift register to the input register without transferring data to the
PMU register (unless the LOAD input is low). This per-
OPERATION
Data stays in input register.
mits the latching of data into the PMU register at a later
time by the LOAD input or subsequent command.
Table 4 summarizes the possible control and address
bit combinations.
When asynchronously latching only one PMU’s data,
the input register of the other PMU maintains the same
data. Therefore, loading both PMU registers would
update the one PMU with new data while the other PMU
remains in its current state.
Mode Selection
Four bits from the control word select between the various modes of operation. INMODE selects between the
two input analog control voltages. F MODE selects
whether the PMU forces a voltage or a current. MMODE
selects whether the DUT current or DUT voltage is
directed to the MSR_ output. HI-ZFORCE places the
driver amplifier in a high-output impedance state. Table
5 describes the various force and measure modes of
operation.
Current-Range Selection
Three bits from the control word, RS0, RS1, RS2, control the full-scale current range for either FI (force cur-
______________________________________________________________________________________
15
MAX9949/MAX9950
Table 1. Bit Order
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
Table 4. PMU Operation Using Control and Address Bits
BIT (3:2)
BIT (1:0)
PMU-B OPERATION
PMU-A OPERATION
A2
A1
C2
C1
0
0
0
0
0
0
0
1
NOP.
Load PMU register A from input register A.
0
0
1
0
Load PMU register B from input register B.
NOP.
0
0
1
1
Load PMU register B from input register B.
Load PMU register A from input register A.
0
1
0
0
NOP.
Load input register A from shift register.
Load input register A and PMU register A
from shift register.
NOP: data just passes through.
0
1
0
1
NOP.
0
1
1
0
Load PMU register B from input register B.
Load input register A from shift register.
0
1
1
1
Load PMU register B from input register B.
Load input register A and PMU register A
from shift register.
1
0
0
0
Load input register B from shift register.
NOP.
1
0
0
1
Load input register B from shift register.
Load PMU register A from input register A.
1
0
1
0
Load input register B and PMU register B
from shift register.
NOP.
1
0
1
1
Load input register B and PMU register B
from shift register.
Load PMU register A from input register A.
1
1
0
0
Load input register B from shift register.
Load input register A from shift register.
1
1
0
1
Load input register B from shift register.
Load input register A and PMU register A
from shift register.
1
1
1
0
Load input register B and PMU register B
from shift register.
Load input register A from shift register.
1
1
1
1
Load input register B and PMU register B
from shift register.
Load input register A and PMU register A
from shift register.
Table 5. PMU Force/Measure Mode Selection
16
(BIT 15)
IN MODE
(BIT 14)
F MODE
(BIT 13)
M MODE
(BIT 8)
HI-ZFORCE
PMU MODE
FORCE
OUTPUT
MEASURE
OUTPUT
ACTIVE
INPUT
0
0
0
1
FVMI
Voltage
IDUT
VIN0
1
0
0
1
FVMI
Voltage
IDUT
VIN1
0
0
1
1
FVMV
Voltage
VDUT
VIN0
1
0
1
1
FVMV
Voltage
VDUT
VIN1
0
1
0
1
FIMI
Current
IDUT
VIN0
1
1
0
1
FIMI
Current
IDUT
VIN1
0
1
1
1
FIMV
Current
VDUT
VIN0
1
1
1
1
FIMV
Current
VDUT
VIN1
X
X
0
0
X
X
1
0
FNMI—Meaningless mode
FNMV
HI-Z
VDUT
______________________________________________________________________________________
X
Dual Per-Pin Parametric Measurement Units
(BIT 12) RS2
(BIT 11) RS1
(BIT 10) RS0
RANGE
0
0
0
±2µA
0
0
1
±2µA
R_E = 1MΩ
0
1
0
±20µA
R_D = 100kΩ
0
1
1
±200µA
R_C = 10kΩ
1
0
0
±2mA
R_B = 1kΩ
1
0
1
±25mA
R_A = 80Ω
1
1
0
External
—
1
1
1
±25mA
R_A = 80Ω
Table 7. Clamp Enable
NOMINAL RESISTOR VALUE
R_E = 1MΩ
Table 8. MSR_ Output Truth Table
CLENABLE
MODE
(BIT 7) HI-ZMSR
HI-Z_
MSR_ STATE
1
Clamps enabled
1
1
Measure output enabled
0
Clamps disabled
0
1
High-Z
1
0
High-Z
0
0
High-Z
rent) or MI (measure current). Table 6 describes the
full-scale current-range control.
Clamp Enable
The CL ENABLE bit enables the force-output voltage
clamps when high and disables the clamps when low.
Table 7 depicts the various clamp mode options.
Measure Output High-Impedance Control
The MSR_ output attains a low-leakage, high-impedance state by using the HI-ZMSR control bit or the HI-Z_
input. The 2 bits are logically ORed together to control
the MSR_ output. The HI-Z_ input allows external multiplexing among several PMU MSR_ outputs without
using the serial interface. Table 8 explains the various
output modes for the MSR_ output.
Digital Output (DOUT)
The digital output follows the last output of the serial
shift register and clocks out on the falling edge of the
input clock. DOUT provides the first bit of the incoming
serial data word 16.5 clock cycles later. This allows for
daisy-chaining an additional device using DOUT and
the same clock.
“Quick Load” Using Chip Select
If CS goes low and then returns high without any clock
activity, the data from the input registers latch into the
PMU registers. This extra function is not standard for
SPI/QSPI/MICROWIRE interfaces. The quick load mimics the function of LOAD without forcing LOAD low.
Comparators
Two comparators configured as a window comparator
monitor the MSR_ output. THMAX_ and THMIN_ set the
high and low thresholds that determine the window.
Both outputs are open drain and share a single disable
control that places the outputs in a high-Z, low-leakage
state. Table 9 describes the comparator output states
of the MAX9949/MAX9950.
Table 9. Comparator Truth Table
(BIT 6) DISABLE
0
CONDITION
DUTH_
DUTL_
X
High-Z
High-Z
1
VMSR > VTHMAX and VTHMIN
0
1
1
VTHMAX > VMSR > VTHMIN
1
1
1
VTHMAX and VTHMIN > VMSR
1
0
1
VTHMIN > VMSR > VTHMAX*
0
0
*VTHMAX > VTHMIN constitutes normal operation. This condition, however, has VTHMIN > VTHMAX and does not cause any problems with
the operation of the comparators.
______________________________________________________________________________________
17
MAX9949/MAX9950
Table 6. Current Range Selection
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
Applications Information
In force-voltage (FV) mode, the output FORCE_ voltage
is directly proportional to the input control voltage. In
force-current (FI) mode, the current flowing out of the
FORCE_ output is proportional to the input control voltage. Positive current flows out of the PMU.
In force-nothing (FN) mode, the FORCE_ output is high
impedance.
In measure-current (MI) mode, the voltage at the MSR_
output is directly proportional to the current exiting the
FORCE_ output. Positive current flows out of the PMU.
In measure-voltage (MV) mode, the voltage at the
MSR_ output is directly proportional to the voltage at
the SENSE_ input.
Current-Sense-Amplifier Offset
Voltage Input
IOS is a buffered input to the current-sense amplifier.
The current-sense amplifier converts the input control
voltage (IN0_ or IN1_) to the forced DUT current (FI)
AND converts the sensed DUT current to the MSR_ output voltage (MI). When IOS equals zero relative to DUTGND (the GND voltage at the DUT, which the
level-setting DACs and the ADC are presumed to use
as a ground reference), the nominal voltage range that
corresponds to ± full-scale current is -4V to +4V. Any
voltage applied to the IOS input adds directly to this
control input/measure output voltage range, i.e., apply-
ing +4V to IOS forces the voltage range that corresponds to ± full-scale current from 0 to +8V.
The following equations determine the minimum and
maximum currents for each current range corresponding to the input voltage or measure voltage:
VMAXCURRENT = VIOS + 4V
VMINCURRENT = VIOS - 4V
Choose IOS so the limits of the MSR_ output do not go
closer than 2.8V to either VEE or VCC. For example, with
supplies of +10V and -5V, limit the MSR_ output to -2.2V
and +7.2V. Therefore, set IOS between +1.8V and +3.2V.
The MSR_ output could clip if IOS is not within this range.
Use these general equations for the limits on IOS:
Minimum VIOS = VEE + 6.8V
Maximum VIOS = VCC - 6.8V
Current Booster for Highest Current Range
An external buffer amplifier can be used to provide a
current range greater than the MAX9949/MAX9950
maximum output current (Figure 5). This function operates as follows.
A digital output decoded from the range select bits,
EXTSEL_, indicates when to activate the booster. The
R_COM output serves as an input to an external buffer
through a 50Ω current-limit series resistor. Each side of
the external current-sense resistor feeds back to RXA_
and RXD_. Ensure that the buffer circuit enters a high-Z
output state when not selected. Any leakage in the
buffer adds to the leakage of the PMU.
Voltage Clamps
50Ω
REXTBOOST
FORCE_
The voltage clamps limit the FORCE_ output and operate over the entire specified current range. Set the
clamp voltages externally at CLHI_ and CLLO_. The
voltage at the FORCE_ output triggers the clamps independent of the voltage at the SENSE_ input. When
enabled, the clamps function in both FI and FV modes.
Current Limit
R_COM
EXTSEL_
RXA_
RXD_
AV = +2
INTERNAL TO MAX9949/MAX9950
Figure 5. External Current Boost
18
The current-limiting circuitry on the FORCE_ output
ensures a well-behaved MSR_ output for currents
between the full current range and the current limits, i.e.,
for currents greater than the full-scale current, the MSR_
voltage is greater than +4V and for currents less than the
full-scale current, the MSR_ voltage is less than -4V.
Independent Control of the Feedback
Switch and the Measure Switch
Two single-pole-double-throw (SPDT) switches determine the mode of operation of the PMU. One switch
______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
RSENSE
IN1_
FORCE_
RSENSE
FORCE_
DUT
DUT
AV = +2
AV = +2
SENSE_
SENSE_
DUTGND
DUTGND
MSR_
MSR_
Figure 6. Force-Voltage/Measure-Current Functional Diagram
Figure 7. Force-Current/Measure-Voltage Functional Diagram
determines whether the sensed DUT current or DUT
voltage feeds back to the input (sensing), and thus
determines whether the MAX9949/MAX9950 force current or voltage. The other switch determines whether the
MSR_ output senses the DUT current or DUT voltage.
input samples the voltage at the DUT and provides a
buffered result at the MSR_ output.
Independent control of these switches and the
HI-ZFORCE state permits flexible modes of operation
beyond the traditional force-voltage/measure-current
(FVMI) and force-current/measure-voltage (FIMV)
modes. The MAX9949/MAX9950 support the following
five modes:
• FVMI
• FIMV
• FVMV
High-Z States
The FORCE_, MSR_, and comparator outputs feature
individual high-Z control that places them into a highimpedance, low-leakage state. The high-Z state allows
busing of MSR_ and comparator outputs with other
PMU measure and comparator outputs. The FORCE_
output high-Z state allows for additional modes of operation as described in Table 5 and can eliminate the
need for a series relay in some applications.
The FORCE_, MSR_, and comparator outputs power up
in the high-Z state.
Input Source Selection and Gating
• FIMI
• FNMV
Figure 6 shows the internal path structure for force-voltage/measure-current mode. In force-voltage/measurecurrent mode, the current across the appropriate
external sense resistor (R_A to R_E) provides a voltage
to the MSR_ output. The SENSE_ input samples the
voltage at the DUT and feeds the buffered result back
to the negative input of the voltage amplifier. The voltage at MSR_ is proportional to the FORCE_ current in
accordance with the following formula:
VMSR_ = IFORCE_ x RSENSE x 2
Figure 7 shows the internal path structure for the forcecurrent/measure-voltage mode. In force-current/measure-voltage mode, the appropriate external sense
resistor (R_A to R_E) provides a feedback voltage to
the inverting input of the voltage amplifier. The SENSE_
Either one of two input signals, IN0_ or IN1_, can control
both the forced voltage and the forced current. In this
case, the two input signals represent alternate forcing
values that can be selected with the serial interface.
Alternatively, each input signal can be dedicated to control a single forcing function (i.e., voltage or current).
Ground, DUT Ground, IOS
The MAX9949/MAX9950 utilize two local grounds,
AGND (analog ground) and DGND (digital ground).
Connect AGND and DGND together on the PC board.
In a typical ATE system, the PMU force voltage is relative to the DUT ground. In this case, reference the input
voltages IN0_ and IN1_ to the DUT ground. Similarly,
reference IOS to the DUT ground. If it is not desired to
offset the current control and measure voltages, connect IOS to the DUT ground potential.
Reference the MSR_ output to the DUT ground.
______________________________________________________________________________________
19
MAX9949/MAX9950
IN1_
MAX9949/MAX9950
Dual Per-Pin Parametric Measurement Units
3) Variations in the power supplies—system implementation determines the variance
VDUT
VEE - 3.5V
VEE - 5V
4) Variation of DUT ground vs. PMU ground—system
implementation determines the variance
Neglecting the effects of the third and fourth items,
Figure 8 demonstrates the force output capabilities
of the PMU.
IDUT
VEE + 5V
VEE + 3.5V
IMIN
IMIN
Figure 8. PMU Force Output Capability
Short-Circuit Protection
The FORCE_ output and SENSE_ input can withstand a
short to any voltage between the supply rails.
Mode and Range Change Transients
The MAX9949/MAX9950 feature make-before-break
switching to minimize glitches. The integrated voltage
clamps also reduce glitching on the output.
DUT Voltage Swing vs. DUT Current and
Power-Supply Voltages
Several factors limit the actual DUT voltage that the
PMU delivers:
1) The overhead required by the amplifiers and other
integrated circuitry—this is typically 3.5V from each
rail for no load current and 5V under full load
2) The voltage drop across the current-range select
resistor and internal circuitry in series with the sense
resistor—at full current, the combined voltage drop is
typically 2.75V
20
Figure 8 indicates that, for zero DUT current, the
DUT voltage swings from (VEE + 3.5V) to (VCC 3.5V). For larger positive DUT currents, the positive
swing drops off linearly until it reaches (VCC - 5V) at
full current. Similarly, for larger negative DUT currents, the negative voltage swing drops off linearly
until it reaches (VEE + 5V) at full current.
Settling Times and Compensation
Capacitors
The data in the Electrical Characteristics table reflects
the circuit shown in the block diagram that includes a
single compensation capacitor (Cx) effectively across all
the sense resistors. Placing individual capacitors, CRA,
C RB, C RC, C RD, and C RE directly across the sense
resistors, R_A, R_B, R_C, R_D, and R_E, independently
optimizes each range.
The combination of the capacitance across the sense
resistors (Cx or CRA, CRB, CRC, CRD, and CRE) and the
main amplifier compensation comparator, CCM, ensures
stability into the maximum expected load capacitance
while optimizing settling time.
Digital Inputs (SCLK, DIN, CS, LOAD)
The digital inputs incorporate hysteresis to mitigate
issues with noise, as well as provide for compatibility
with opto-isolators that can have slow edges.
Chip Information
PROCESS: BiCMOS
______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
CS
LOAD
SCLK
DIN
DUTHB
DUTLB
EXTBSEL
DGND
DOUT
VL
DGND
EXTASEL
DUTLA
DUTHA
HI-ZB
HI-ZA
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
+
48 VEE
VEE
1
VCC
2
47 VCC
RXAB
3
46 RXAA
RXDB
4
45 RXDA
CC2B
5
44 CC2A
CC1B
6
43 CC1A
SENSEB
7
42 SENSEA
FORCEB
8
RBA
41 FORCEA
MAX9949
9
40 RAA
RBB 10
39 RAB
RBC 11
38 RAC
RBD 12
37 RAD
RBE 13
36 RAE
35 RACOM
RBCOM 14
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
CLLOB
IN0B
IN1B
MSRB
AGND
IOS
MSRA
IN1A
IN0A
CLLOA
CLHIA
THMINA
THMAXA
33 VEE
CLHIB
VEE 16
THMINB
34 VCC
THMAXB
VCC 15
______________________________________________________________________________________
21
MAX9949/MAX9950
MAX9949 Pin Configuration
Dual Per-Pin Parametric Measurement Units
THMAXB
THMINB
CLHIB
CLLOB
IN0B
IN1B
MSRB
AGND
IOS
MSRA
IN1A
IN0A
CLLOA
CLHIA
THMINA
THMAXA
MAX9949/MAX9950
MAX9950 Pin Configuration
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
+
48 VEE
VEE
1
VCC
2
47 VCC
RBCOM
3
46 RACOM
RBE
4
45 RAE
RBD
5
44 RAD
RBC
6
43 RAC
RBB
7
42 RAB
RBA
8
FORCEB
41 RAA
MAX9950
9
40 FORCEA
SENSEB 10
39 SENSEA
18
19
20
21
22
23
24
25
26
27
28
29
30
31
DUTLA
DUTHA
HI-ZB
32
HI-ZA
17
EXTASEL
33 VEE
DGND
VEE 16
VL
34 VCC
DOUT
VCC 15
DGND
35 RXAA
EXTBSEL
RXAB 14
DUTLB
36 RXDA
DUTHB
RXDB 13
DIN
37 CC2A
SCLK
CC2B 12
LOAD
38 CC1A
CS
CC1B 11
Package Information
For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages.
22
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
64 TQFP-EPR
C64E-9R
21-0162
64 TQFP-EP
C64E-6
21-0084
______________________________________________________________________________________
Dual Per-Pin Parametric Measurement Units
REVISION
NUMBER
REVISION
DATE
2
3/09
DESCRIPTION
Corrected timing diagrams and changed to lead-free package.
PAGES
CHANGED
1, 13, 14
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 23
© 2009 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX9949/MAX9950
Revision History