www.fairchildsemi.com RC7352 Parametric Measurement Unit Features • High resolution voltage measurement (±0.05%) and accuracy: (±10mV max. offset) and 0.5% gain error • Internal current limit for ranges (A, B, & C) • Force voltage/measure current and force current measure voltage functions • Forced voltage range (-5V to +15V) • Four programmable measured current ranges: Range A = ±20mA max Range B = ±200mA max Range C = ±1.0mA max Range D = ±40mA max • High resolution current force/measure ±0.05% = 2 bits • Internal control circuitry for selecting ranges • High accuracy: 12 bit linearity and 0.5% gain error • High current range D current limit protection set externally by the value of resistor RDIL • Measurement output voltage can be disabled • Forced current ranges: Range A = ±20mA max Range B = ±200mA max Range C = ±1.0mA max Range D = ±40mA max • Measured voltage range: -5V to +15V Applications • ATE pin electronics measurements • Instrumentation, meters • Programmable voltage or current supply Description The RC7352 is a “Per Pin” Parametric Measurement Unit (PMU) that can force voltage and measure current or force current and measure voltage. The RC7352 forces voltages from +15V to -5V when +VS is 20V and –VS is -10V, or currents up to ±40mA. All logic inputs for the RC7352 are TTL compatible, while the open collector logic outputs are TTL/CMOS compatible. Setting the SI/V (Select I/V) pin low puts the RC7352 in the force voltage and measure current mode. The resulting output voltage at the DUT matches the input applied to the Block Diagram 6 CA 18 VIN 25 CB 7 I/VOUT RANGE A IN OUT V/I FORCE – + 23 CAP_V + I SENSE CAP – + 11 4:1 MUX I – V – + 17 I/VIN CAP_I 28 +VS (20V) 20 VFB + + – + I – – + A=4 – I I I – – I I 10 RADJ V/I MEAS. – + – + + – I WINDOW COMPARATOR – I: FI/MV V: FV/MI + – + I – E I V I I LOGIC & BIAS + – + – E I + + – I + RA EN RANGEA.SCH – + IA RANGE B IN OUT EN RANGEB.SCH – + IB V + – + RANGE C IN OUT EN RANGEC.SCH – + IC RANGE D IN OUT EN – + ID D2 RDIL RANGED.SCH 4 I/V MX 26 I/V MN 12 RS1 27 VLS 5 VHS 13 SI/V 21 VDIS 14 RS2 19 RB 22 RC 24 RD 1 2 D RDIL /4 15 I/V M 9 8 GND 16 -VS (-10V) 3 VEE (-10V) 65-7352-01 Rev. 1.1.2 RC7352 PRODUCT SPECIFICATION composite signal. Additionally the VDIS pin can be set high to disable the window comparator and its I/O lines. Although this reduces overall power consumption, it also disables the I/VM output. I/VIN pin (please refer to block diagram). The I/VM pin provides a voltage proportional to the DUT current. V(I/VM) = (4 x R x I(DUT)), where R is the external range resistor (0.05% tolerance) and I(DUT) is the current supplied to the load. The resistors in the application circuit were chosen using this formula R range = (2V/Imax), for Range A this is RA = 2/20 mA or 100K. Table 1. Maximum Output Current on Pin Select When SI/V is high the RC7352 will force current and measure voltage. The range select pins RS1 and RS2 control the maximum output current (see Table 1), while magnitude of the forced current is given by the expresion SI/V RS2 RS1 Mode I(DUT) = V(I/VIN)/(4 x R) where R is the range resistor. In the FI/MV mode the voltage at the I/VM pin equals the device voltage. The I/VM pin can be connected to an A/D convertor to monitor the current or voltage at the load device. The RC7352 also has a window comparator that can provide upper or lower limit fail information. I/Vmx and I/Vmn are voltage inputs for the upper and lower limits respectively. You must use the formulas listed above to calculate current limits for each range while voltage limits are 1:1. Their corresponding outputs, VHF (V high fail) and VLF (V low fail) can be used individually or “Wire ORed” to obtain a 0 0 0 FV/MI Range A, Imax = ±20 mA 0 0 1 FV/MI Range B, Imax = ±200 mA 0 1 1 FV/MI Range C, Imax = ±1.0 mA 0 1 0 FV/MI Range D, Imax = ±40 mA 1 0 0 FI/MV Range A, Imax = ±20 mA 1 0 1 FI/MV Range B, Imax = ±200 mA 1 1 1 FI/MV Range C, Imax = ±1.0 mA 1 1 0 FI/MV Range D, Imax = ±40 mA Notes: 1. FV/MI = Force Voltage Measure Current. 2. FI/MV = Force Current Measure Voltage. 3. +VS–5 ³ VOUT ³ –VS+5 2 VEE RDIL D +VS VLF 4 3 2 1 28 27 I/VMN I/VMX Pin Assignments VHF 5 26 25 CB CA 6 24 RD IVOUT 7 23 I/VIN GND 8 22 RC RA 9 21 VDIS RADJ 10 20 VFB CAP_I 11 19 18 17 CA 16 CAP_V 15 –VS RS1 14 RS2 13 I/VM 12 SI/V RC7352 RB 65-7352-02 PRODUCT SPECIFICATION RC7352 Pin Description Pin Name Pin Number Pin Description +VS 28 +VS should be bypassed to ground with a 10.0 mF tantalium capacitor placed as close to the pin as possible. -VS 16 –VS should be bypassed to ground with a 10.0 mF tantalium capacitor placed as close to the pins as possible. VEE 3 VEE is the negative supply for range D. This pin should be bypassed with a 0.1 mF ceramic capacitor to ground. GND 8 This pin should be connected to the printed circuit board’s ground plane. I/VIN 23 Input reference voltage for VOUT or IOUT. In the force voltage measure current mode (FV/MI) V(I/VOUT) = V(I/VIN ) and V(I/VM) = 4 x IOUT x R Where IOUT is the device output current and R is the range resistor. In the Force Current/Measure Voltage Mode V ( I ¤ VIN ) I OUT = -----------------------4´R V(I/VM) = V(I/VOUT) I/VOUT 7 The Load or Device under test is connected to I/VOUT. The current to the load is supplied via the appropriate range resistor with I/VOUT serving as the voltage feedback point for the PMUs internal instrumentation amplifier. SI/V 13 A TTL/CMOS signal applied to this pin selects either Force Voltage/Measure Current or Force Current/Measure Voltage mode. A TTL/CMOS low level will select Force Voltage/Measure Current function. A TTL/CMOS high level selects Force Current/ Measure Voltage mode. RA 9 Resistor RA should be placed between RA and I/VOUT. RA tolerance should be better than +0.05% to improve gain error. Maximum current for range A is shown in the equation below. ± 2V I A = ----------RA The ±2 volts represents the maximum voltage VA across RA. For Range A, IA should not exceed ±20 mA, i.e., RA should be higher than or equal to 100 kW. A metal film resistor should be used to reduce inherent resistor noise (schott and pop corn noise) and improve resolution. For maximum stability, a 300 pF capacitor should be connected across RA. RB 19 For Range B, IB should not exceed ±200 mA, i.e., RB should be higher than or equal to 10 kW with ±0.05% tolerance. For maximum stability a 1,000 pF capacitor should be connected across RB. RC 22 For Range C, IC should not exceed ±1 mA, i.e., RC should be higher than or equal to 2 kW with ±0.05% tolerance. RD 24 For Range D, ID should not exceed ±40 mA, i.e., RD should be higher than or equal to 50 W with ±0.05% tolerance. 1 Two diodes must be connected between D & RD as shown in the block diagram. D CA, CB RDIL 6, 25 2 A 30pF capacitor placed between these pins will improve stability. Range D output for current limiting. An external resistor is connected between RDIL and D to limit current to a value ILIM = 0.8V/RLM. 3 RC7352 PRODUCT SPECIFICATION Pin Description (continued) Pin Name 4 Pin Number Pin Description RS1, 12 RS2 14 RS1 and RS2 are TTL or CMOS compatible. The truth table below shows the range selection table. RS1 RS2 Range Selected L L A L H B H H C H L D I/VMX, I/VMN 4 26 The voltage applied to pin 4 sets the upper current or voltage limit for the measurement at pin 15 I/VM. To set the desired limit for current measurement a voltage equaling (4 x IL x R) must be applied on this pin. R is the external resistor of the selected range (A, B, C, or D). For voltage measurement the voltage applied to this pin is the limit. VHF 5 VHF, High Fail, is an open collector output that requires a pull-up to the logic supply. If the voltage at pin 15, I/VM, is greater than the threshold voltage at pin 4, I/VMX, VHF will become a logic low. The open collector structure makes wire-ORing of multiple PMU’s possible. Connect a 3,000 pF capacitor to GND to minimize oscillation at the cross-over point. VLF 29 VLF mirror VHF for the lower threshold I/VMN. Connect a 3,000 pF capacitor to GND to minimize oscillation at the cross over point. VDIS 21 When VDIS is tied to ground output I/VM, VHF and VLF are enabled. If VDIS is open VHF and VLF will require external pullups to maintain a logic high. And I/VM will be in a high impedance state. I/VM 15 In the Force Voltage/Measure Current mode this output voltage is equal to four times the voltage across external resistor R of selected range A, B, C, or D through which the measured current is flowing ((I/V)M = 4.0 x IM x R). In the Force Current/ Measure Voltage mode this output is equal to the voltage at I/V out. This output can be disabled by applying a TTL HI on the VDIS pin. (Pin 21) VFB 20 VFB, voltage feedback, is the buffered output voltage, I/V OUT. This pin should not be loaded. Connect a 50K 1% resistor from VFB to CAP_V. RADJ 10 The RADJ pin is provided to adjust the offset for the ISENSE function. The best accuracy for V/IM is obtained when RADJ is shorted to analog ground. The point is terminated with a 100 W resistor in the block diagram. CAP_I CAP_V CA 11 18 17 CA is the common point for two 50 pF compensation capacitors that improve the stability of the PMU. These components are optional and can be omitted for some loads. RC7352 PRODUCT SPECIFICATION Absolute Maximum Ratings1 Parameter Min. Max. Units 32 V -2 +6 V I/VMN £ +VS –VS £ I/VMX V –VS £I/VIN £ +VS V Absolute Difference, +VS+|–VS| Digital Control Inputs SI/V, RS1, RS2, VDIS Comparator Inputs I/VMN, I/VMX I/VIN Notes: 1. Absolute maximum ratings are limiting values applied individually while all other parameters are within specified operating conditions. Functional operation under any of these conditions is NOT implied. 2. Applied voltage must be current limited to specified range, and measured with respect to GND. 3. Forcing voltage must be limited to specified range. 4. Current is specified as conventional current flowing into the device. Recommended Operating Conditions Symbol Parameters TC Case operating temperature +VS Positive supply voltage1 –VS Negative supply Min. Max. Units 70 °C 10.4 20.0 20.6 V -15.75 -10.0 -9.5 V 0 voltage1 D2 VEE Negative supply voltage for range RA Resistor for IA current range 100 2000 RB Resistor for IB current range 10 200 KW RC Resistor for IC current range 2 40 KW RD Resistor for ID current range 50 1000 W Notes: 1. +VS + |–VS| £ 30V +VS + |–VS| ³ 24 2. –VS & VEE are always at the same voltage. 5 Typ. –VS V KW PRODUCT SPECIFICATION RC7352 DC Electrical Characteristics +VS = 20V ±3%, –VS = -10V ±5% TA = 25°C, and external ±0.05% tolerance resistors RA = 1000kW, RB = 10kW, RC = 2kW, and RD = 50W unless otherwise specified. Symbol Parameters Test Conditions Min. Typ. Max. Units +8 V Forced Current/Measure Voltage I/VIN Input Voltage Range For Setting Forced Current (IF) I/VM Measured Voltage Output @ (I/V)M All ranges, full scale current -5 +15 V Output Sink/Source Current (I/V)M = -5V, +15V -200 +200 mA -.05 ±0.025 +0.05 %FSR I/VFIN = 4 x IF x R -8 VMR Voltage Measured Resolution VOR Voltage Measurement Offset I/VIN = 0V; Measured @ I/VM -6.0 ±2 +6.0 mV VGE Voltage Gain Error Gain of 4 -2.0 +0.5 +2.0 % CMRR1 IOUT Error Due to Common Mode Load Voltage -5V £ I/VOUT £ +15V; Measured @ (I/V)M 45 60 IOER dB Forced Voltage/Measure Current I/VIN Force Input Voltage Range All ranges, full scale current I/VFVOS Forced Voltage Offset I/VIN = 0V, measure I/VOUT and VFB -5 -6.0 +15 V +6.0 mV ±0.025 ±0.05 FSR% Forced Voltage Linearity Error CMRR2 ±2 IOUT Measure Error Due to I/VM Common Mode Voltage -FSR £ IOUT £ +FSR; Measured @ (I/V)M 45 VLER I/VOUT Forced Output Voltage Range All ranges, full scale current -5 +15 V I/VM Voltage Output Equivalent to Measured Current: (I/V)M = 4 x IF x R All ranges, full scale voltage -8 +8 V I I measured; I = (I/VM)/(4R) I/VM = -8.0V, +8.0V; full scale -200 +200 mA ±20 mA 60 dB Current Ranges Range A IA Maximum Full Scale Current RA = 100kW (0.05%) IAMR Current Measurement Resolution guaranteed by design ILIN Linearity3 lGE Current Gain Error4 IFIOS IMIOS Force Current ±0.025 % -0.05 ±0.025 +0.05 Offset5 Measure Current Offset6 -2.0 0.5 +2.0 % I/VIN = 0V -25 ±10 +25 nA I/VIN = 0V -25 ±10 +25 nA ±200 mA Range B IB Maximum Full Scale Current RB = 10kW (0.05%) guaranteed by design IBMR Current Measurement Resolution ILIN Linearity3 lGE Current Gain Error4 ±0.025 % -0.05 ±0.025 +0.05 Offset5 IFIOS Force Current IMIOS Measure Current Offset6 -2.0 ±0.5 +2.0 % -250 ±100 +250 nA -250 ±100 +250 nA 6 RC7352 PRODUCT SPECIFICATION DC Electrical Characteristics (continued) Symbol Parameters Test Conditions Min. Typ. Max. Units ±1 mA Range C IC Maximum Full Scale Current RC = 2kW (0.05%) ICMR Current Measurement Resolution guaranteed by design ILIN Linearity3 -0.05 ±.025 +0.05 % lGE Current Gain Error4 -2.0 ±0.5 +2.0 % IFIOS Force Current Offset5 -1.5 ±0.5 +1.5 mA IMIOS Measure Current Offset6 -1.5 ±0.5 +1.5 mA ±40 mA ±.025 % Range D IC Maximum Full Scale Current RD = 50W (0.05%) IDMR Current Measurement Resolution Current Measurement Accuracy guaranteed by design ILIN Linearity3 -0.05 ±.025 +0.05 % lGE Current Gain Error4 -2.0 ±0.5 +2.0 % IFIOS Force Current Offset5 -50 ±20 +50 mA -50 ±20 +50 mA 0.8 1.4 2.0 V IMIOS Measure Current Offset6 ±.025 % Digital Control Inputs (SI/V, RS1, RS2) VIH Internal Threshold Voltage ILH Logic High Bias Current VH = 2.0V 200 nA ILL Logic Low Bias Current VL = 0.8V 2.0 nA Digital Control Input VDIS VIH Internal Threshold Voltage ILH Logic High Bias Current VH = 2.0V 1.0 mA ILL Logic Low Bias Current VL = 0.8V 2.0 nA 0.8 1.4 2.0 V Comparator Input; I/VMAX, I/VMIN I/VMX,MN Input Voltage Range -8.0 +15 V IH Input Bias Current (Logic High) VH = +15V 0.4 mA IL Input Bias Current (Logic Low) VL = 0.8V 0.4 mA Comparator Status Outputs; VHF, VLF VOH Output Voltage (Logic High) RPULLUP = 10kW VOL Output Voltage (Logic Low) RPULLUP = 10kW IOH Output Current High VOUT = 5.0V 0.1 IOL Output Current Low IZ Output Leakage Current Disable State VOUT = 5.0V 0.1 I+ (1.0) Positive Supply Current No load Range A 4.0 11.0 mA I- (2.0) Positive Supply Current No load Range A 4.0 11.0 mA 3.5 V 0.8 V mA 1.0 mA mA Other Notes: 1. CMRR is measured with VL=15V/-5V; R is RA, RB, RC or RD; V1 = constant; This parameter is to define the IOUT current error due to the VL common mode voltage for a constant V1. This parameter is guaranteed to full V1 range. (±8V) æ DI OUT ´ 4 ´ Rö CMRR = 20 log ç --------------------------------------÷ DV L è ø 7 RC7352 PRODUCT SPECIFICATION IOUT R VL I/VOUT I/VIN FI/MV I/VM V1 65-7352-03 2. CMRR is measured with V1 = +15V/-5V; R is RA, RB, RC or RD; IOUT = constant. This parameter is to define the current measurement error due to the input voltage V1. It guarantees all ranges and ± full scale IOUT. æ DV Mö CMRR = 20 log ç ------------÷ è DV 1 ø IOUT RL R I/VOUT I/VIN I/VM VM FV/MI V1 65-7352-04 3. Linearity is measured against two point straight line calibration with five measurement points. 4. Current Gain Error is measured with –full scale current to +full scale current. The ideal gain is 4. VM 2 – VM 1 Current Gain Error = ------------------------------------------------R ( I OUT2 – I OUT1 ) 5. Force current is measured with I/VOUT to ground with I/VIN = 0V. 6. Measured current offset is measured with I/VIN = 0V, Offset = (I/VM)/4R where R is RA, RB, RC, and RD. 8 PRODUCT SPECIFICATION RC7352 AC Electrical Characteristics +VS = 20V ±3%, -VS = -10V ±5%, TA = 25°C, and external ±0.05% tolerance resistors RA = 100kW, RB = 10kW, RC = 2kW, and RD = 50W unless otherwise specified. Symbol Parameters Test Conditions Min. Typ. Max. Units Comparator tHL Response Time High to Low RLOAD = 10k, 5mV Overdrive 1.1 ms tLH Response Time Low to High RLOAD = 10k, 5mV Overdrive 450 ns Response Time (setting time)1 Range A 2.4 ms Force Current/Measure Voltage Range B 2.3 Range C 2.6 Range D 2.6 Differential Amplifier tMZF Voltage @ I/VM = -5.0V to +15V IF = Max tMZF Response Time (settling time)1 Ranges A 2.4 Force Voltage/Measure Current Ranges B 2.5 Ranges C 2.6 Ranges D 2.7 ms Voltage @ I/VOUT = 5.0V to +15V IM = Max tMZF Response Time (Settling time)1 Ranges A, B, C, & D 1.0 3 ms Voltage @ I/VOUT = -2.0V to +6.0V 30pF from CA to CB No Load tDS Output Disable to Enable Time 20 ms Notes: 1. Response Time (settling time) for Force Current/Measure Voltage mode is measured with 30pF from CA to CB and I/V IN Voltage Swings from -8.0V to +8.0V, and RL value for Range placed between I/VOUT and 5V. 500KW 50KW 10KW 250W A B C D 9 RC7352 PRODUCT SPECIFICATION Application Example C4 * 5V +20V VPOS +VS C6 1pF R13 100K RANGE D CURRENT LIMIT VOUT LOW FAIL D1 6.8uF VOUT LOW LIMIT C7 3nF 1N4148 D2 I/VMX X0 VOUT UPPER LIMIT R15 16 5V 2 R13 3 100K 4 5 VOUT HIGH FAIL VHF 1 C5 3nF 6 C1 1nF 7 GND 8 R17 9 ¨ 100 5V R9 R8 R7 100K I/VIN 28 RDIL VLF VEE I/VMN 26 I/VMX CB 25 VHF RD 24 I/VIN 23 RC 22 VDIS 21 VFB 20 CA I/VOUT GND RA RADJ RB 19 11 CAP_I CAP_V 18 12 RSI 13 SI/V -VS 16 RS2 V/IM 15 SI/V 2K R10 R16 DUT or LOAD 10K C3 50K * CV 50pF 1nF C9 300pF R6 100K 50pF RS1 S1 R12 50 R11 CI* 100K GND DUT GND VDIS VHS VLS I/VM L OUTPUTS ENABLED H OUTPUTS DISABLED VOLT/CURRENT MEASUREMENT RS2 RS1 RS2 RANGE L L A +/-20uA L H B +/-200uA H H C +/-1mA H L D +/-40mA 10 V/IM -VS VNEG -10V I/VIN * R13 100K 17 CAP R18 100K 5V 27 10 14 100K * +VS I/VMN C8 1nF 1N4148 D1&2 VLF C2 6.8uF SI/V FUNCTION L FORCE VOLTAGE H FORCE CURRENT * OPTIONAL PART ¨ SHORT RADJ TO GND FOR BEST DC ACCURACY 65-7352-05 PRODUCT SPECIFICATION RC7352 Mechanical Dimensions Inches Symbol Min. A A1 A2 B B1 D/E D1/E1 D3/E3 e J ND/NE N ccc Max. .165 .180 .090 .120 .020 — .013 .021 .026 .032 .485 .495 .450 .456 .300 BSC .050 BSC .042 .048 7 28 — .004 Notes: Millimeters Min. Notes 1. All dimensions and tolerances conform to ANSI Y14.5M-1982. Max. 4.19 4.57 2.29 3.05 .51 — .33 .53 .66 .81 12.32 12.57 11.43 11.58 7.62 BSC 1.27 BSC 1.07 1.22 7 28 — 0.10 2. Corner and edge chamfer (J) = 45¡. 3. Dimension D1 and E1 do not include mold protrusion. Allowable protrusion is .101" (.25mm). 3 2 E E1 D J D1 D3/E3 B1 J e A A1 A2 B –C– LEAD COPLANARITY ccc C 11 RC7352 PRODUCT SPECIFICATION Ordering Information Part Number Package RC7352QA 28-pin PLCC LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com 7/24/98 0.0m 002 Stock#DS30007352 Ó 1998 Fairchild Semiconductor Corporation