ISL28006

Micropower, Rail to Rail Input Current Sense Amplifier with Voltage Output ISL28006 The ISL28006 is a micropower, uni-directional high-side and low-side current sense amplifier featuring a proprietary rail-to-rail input current sensing amplifier. The ISL28006 is ideal for high-side current sense applications where the sense voltage is usually much higher than the amplifier supply voltage. The device can be used to sense voltages as high as 28V when operating from a supply voltage as low as 2.7V. The micropower ISL28006 consumes only 50µA of supply current when operating from a 2.7V to 28V supply. The ISL28006 features a common-mode input voltage range from 0V to 28V. The proprietary architecture extends the input voltage sensing range down to 0V, making it an excellent choice for low-side ground sensing applications. The benefit of this architecture is that a high degree of total output accuracy is maintained over the entire 0V to 28V common mode input voltage range. The ISL28006 is available in fixed (100V/V, 50V/V, 20V/V and Adjustable) gains in the space saving 5 Ld SOT-23 package and the 6 Ld SOT-23 package for the adjustable gain part. The parts operate over the extended temperature range from -40°C to +125°C. ISL28006 Features • Low Power Consumption . . . . . . . . . . . . . 50µA,Typ • Supply Range. . . . . . . . . . . . . . . . . . . 2.7V to 28V • Wide Common Mode Input . . . . . . . . . . . 0V to 28V • Gain Versions - ISL28006-100 . - ISL28006-50. . - ISL28006-20. . - ISL28006-ADJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........... ........... ........... .ADJ (Min Gain . 100V/V . . 50V/V . . 20V/V = 20V/V) • Operating Temperature Range . . . . -40°C to +125°C • Packages . . . . . . . . . . . . 5 Ld SOT-23, 6 Ld SOT-23 Applications*(see page 23) • Power Management/Monitors • Power Distribution and Safety • DC/DC, AC/DC Converters • Battery Management/Charging • Automotive Power Distribution Related Literature*(see page 23) • See AN1532 for “ISL28006 Evaluation Board User’s Guide” Typical Application SENSE +12VDC RSENSE +12VDC OUTPUT +5VDC ISL28006 + ISENSE +12VDC Gain Accuracy vs VRS+ = 0V to 28V 0.6 0.4 0.2 ACCURACY (%) 0 -0.2 -0.4 -0.6 -0.8 -1 -1.2 -1.4 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 +100°C -40°C +25°C +125°C GAIN 100 SENSE +5VDC RSENSE +5VDC OUTPUT +5VDC ISENSE +5VDC +1.0VDC OUTPUT ISENSE +1.0VDC ISL28006 + SENSE +1.0VDC MULTIPLE OUTPUT POWER SUPPLY GND RSENSE +5VDC ISL28006 + VRS+ (V) May 27, 2010 FN6548.3 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2010. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL28006 Block Diagram VCC I = 2.86µA VSENSE RS+ R1 RSR2 + OUT Rf Rg gmHI HIGH-SIDE AND LOW-SIDE SENSING VCC I = 2.86µA VSENSE RS+ R1 RSR2 1.35V R3 + OUT Rf FB gmLO IMIRROR R5 VSENSE GND Rg gmHI HIGH-SIDE AND LOW-SIDE SENSING 1.35V R3 gmLO R5 VSENSE R44 R IMIRROR GND R44 R FIXED GAIN PARTS ADJUSTABLE GAIN PART Pin Configurations ISL28006-100, 50, 20 (5 LD SOT-23) TOP VIEW GND 1 OUT 2 VCC 3 FIXED GAIN 4 RS+ 5 RS- ISL28006-ADJ (6 LD SOT-23) TOP VIEW FB 1 OUT 2 VCC 3 ADJ. GAIN 6 GND 5 RS4 RS+ Pin Descriptions ISL28006-100, 50, 20 (5 LD SOT-23) 1 2 3 4 5 ISL28006-ADJ (6 LD SOT-23) 6 1 2 3 4 5 FB VCC RS- PIN NAME GND FB OUT VCC RS+ RSPower Ground DESCRIPTION Input Pin for External Resistors Amplifier Output Positive Power Supply Sense Voltage Non-inverting Input Sense Voltage Inverting Input CAPACITIVELY COUPLED ESD CLAMP OUT RS+ GND 2 FN6548.3 May 27, 2010 ISL28006 Ordering Information PART NUMBER (Notes 1, 2, 3) ISL28006FH100Z-T7 ISL28006FH50Z-T7 ISL28006FH20Z-T7 ISL28006FHADJZ-T7 ISL28006FH-100EVAL1Z ISL28006FH-50EVAL1Z ISL28006FH-20EVAL1Z ISL28006FH-ADJEVAL1Z NOTES: 1. Please refer to TB347 for details on reel specifications. 2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 3. For Moisture Sensitivity Level (MSL), please see device information page for ISL28006. For more information on MSL please see techbrief TB363. 4. The part marking is located on the bottom of the part. GAIN 100V/V 50V/V 20V/V ADJ PART MARKING (Note 4) BDJA BDHA BDGA BDFA PACKAGE Tape & Reel (Pb-Free) 5 Ld SOT-23 5 Ld SOT-23 5 Ld SOT-23 6 Ld SOT-23 PKG. DWG. # P5.064A P5.064A P5.064A P6.064 100V/V Evaluation Board 50V/V Evaluation Board 20V/V Evaluation Board Adjustable Evaluation Board 3 FN6548.3 May 27, 2010 ISL28006 Absolute Maximum Ratings Max Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 28V Max Differential Input Current . . . . . . . . . . . . . . . . . 20mA Max Differential Input Voltage . . . . . . . . . . . . . . . . . .+0.5V Max Input Voltage (RS+, RS-, FB). . . . . . . GND - 0.5V to 30V Max Input Current for Input Voltage 2V, VSENSE = 5mV 50 62 63 ADJ Gain = 21 Rf = 100kΩ, Rg = 5kΩ VCC Slew Rate Supply Voltage Gain = 100 Gain = 50 Gain = 20 ADJ Gain = 21 Rf = 100kΩ, Rg = 5kΩ VRS+ > 2V, VSENSE = 5mV 50 62 63 Guaranteed by PSRR Pulse on RS+ pin, VOUT = 8VP-P (Figure 65) Pulse on RS+ pin, VOUT = 8VP-P (Figure 65) Pulse on RS+ pin, VOUT = 3.5VP-P (Figure 65) Pulse on RS+ pin, VOUT = 3.5VP-P (Figure 65) 2.7 0.58 0.58 0.50 0.50 0.76 0.67 0.67 0.67 28 -1.41 -1.41 -1.25 0.7 0.9 1.8 2.3 1.05 1.2 1.8 2.3 50 50 TYP MAX (Note 7) UNIT 0.7 0.9 % % % % % % % % % % % mV mV Ω mA mA µA µA µA µA µA µA V V/µs V/µs V/µs V/µs PARAMETER VOA (Total Output Accuracy) DESCRIPTION Gain = 100 (Note 11) Short Circuit Sourcing Current VCC = VRS+ = 5V, RL = 10Ω Short Circuit Sinking Current Gain = 100 VCC = VRS+ = 5V, RL = 10Ω VRS+ > 2V, VSENSE = 5mV 6 FN6548.3 May 27, 2010 ISL28006 Electrical Specifications VCC = 12V, VRS+ = 0V to 28V, VSENSE = 0V, RLOAD = 1MΩ, TA = +25°C unless otherwise specified. Boldface limits apply over the operating temperature range, -40°C to +125°C. Temperature data established by characterization. (Continued) CONDITIONS VRS+ = 12V, 0.1V, VSENSE = 100mV VRS+ = 12V, 0.1V, VSENSE = 100mV VRS+ = 12V, 0.1V, VSENSE = 100mV VRS+ = 12V, 0.1V, VSENSE = 100mV, Rf = 100kΩ, Rg = 1kΩ VRS+ = 12V, VSENSE = 100mV, Rf = 100kΩ, Rg = 2kΩ VRS+ = 0.1V, VSENSE = 100mV, Rf = 100kΩ, R g = 2k Ω ADJ, Gain = 21 (Figure 57) VRS+ = 12V, VSENSE = 100mV, Rf = 100kΩ, Rg = 5kΩ VRS+ = 0.1V, VSENSE = 100mV, Rf = 100kΩ, R g = 5k Ω tS Output Settling Time to 1% of VCC = VRS+ = 12V, VOUT = 10V step, Final Value VSENSE > 7mV VCC = VRS+ = 0.2V, VOUT = 10V step, VSENSE > 7mV Capacitive-Load Stability tS Power-up No sustained oscillations MIN (Note 7) TYP 110 160 180 40 78 122 131 237 15 20 300 15 50 10 MAX (Note 7) UNIT kHz kHz kHz kHz kHz kHz kHz kHz µs µs pF µs µs µs PARAMETER BW-3dB DESCRIPTION Gain = 100 Gain = 50 Gain = 20 ADJ, Gain = 101 (Figure 57) ADJ, Gain = 51 (Figure 57) Power-Up Time to 1% of Final VCC = VRS+ = 12V, VSENSE = 100mV Value VCC = 12V, VRS+ = 0.2V VSENSE = 100mV Saturation Recovery Time VCC = VRS+ = 12V, VSENSE = 100mV, overdrive NOTES: 7. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization and are not production tested. 8. DEFINITION OF TERMS: • VSENSEA = VSENSE @ 100mV • VSENSEB = VSENSE @ 20mV • VOUTA = VOUT @ VSENSEA = 100mV • VOUTB = VOUT @ VSENSEB = 20mV ⎛ V OUT A – V OUT B ⎞ • G = GAIN = ⎜ -------------------------------------------------------------⎟ ⎝ V SENSE A – V SENSE B⎠ V OUT A 9. VOS is extrapolated from the gain measurement. V OS = V SENSE A – ------------------G ⎛ G MEASURED – G EXPECTED⎞ 10. % Gain Accuracy = GA = ⎜ ------------------------------------------------------------------------------ ⎟ × 100 G EXPECTED ⎝ ⎠ ⎛ VOUT MEASURED – VOUT EXPECTED⎞ 11. Output Accuracy % VOA = ⎜ --------------------------------------------------------------------------------------------------------- ⎟ × 100 where VOUT = VSENSE X GAIN and VSENSE = 100mV VOUT EXPECTED ⎝ ⎠ 7 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 1.8 1.6 1.4 1.2 VOLTS (V) 1.0 0.8 0.6 0.4 0.2 0 0 0.2 0.4 0.6 0.8 1.0 1.2 TIME (ms) 1.4 1.6 1.8 VRS+ Vcc = 12V, RL = 1M, unless otherwise specified. 2.4 VRS+ 2.0 12 10 8 6 4 2 0 2.0 VOUT (V) VTH(L-H) = 1.52V VRS+ (V) VTH(H-L) = 1.23V 1.6 1.2 0.8 G100, VOUT = 1V G50, VOUT = 500mV G20, VOUT = 200mV 2.0 0.4 0 VOUT (G = 100) RL = 1M VCC = 12V VOUT (G = 100) G100, VOUT = 2V G50, VOUT = 1V G20, VOUT = 400mV 0 0.2 0.4 0.6 0.8 1.0 1.2 TIME (ms) 1.4 1.6 1.8 FIGURE 1. HIGH-SIDE and LOW-SIDE THRESHOLD VOLTAGE VRS+(L-H) and VRS+(H-L), VSENSE = 10mV FIGURE 2. VOUT vs VRS+, VSENSE = 20mV TRANSIENT RESPONSE 12 GAIN 100 10 8 VOUT (V) VOUT (V) 6 4 2 0 12 GAIN 100 10 8 6 4 2 0 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 TIME (µs) 40 50 60 TIME (µs) 70 80 90 100 FIGURE 3. LARGE SIGNAL TRANSIENT RESPONSE VRS+ = 0.2V, VSENSE = 100mV FIGURE 4. LARGE SIGNAL TRANSIENT RESPONSE VRS+ = 12V, VSENSE = 100mV 20 GAIN 100 18 VSENSE = 20mV, 100mV 16 14 UNITS 12 10 8 6 4 2 0 -250 -200 -150 -100 -50 VOS (µV) 0 50 100 VOS (µV) 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 -200 -400 GAIN 100 VSENSE = 20mV, 100mV +125°C +100°C -40°C 0 2 4 6 8 +25°C 10 12 14 16 18 20 22 24 26 28 VRS+ (V) FIGURE 5. VOS (µV) DISTRIBUTION AT +25°C, VRS+ = 12V, QUANTITY: 100 FIGURE 6. VOS vs VRS+ 8 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 -200 -400 GAIN 100 VSENSE = 20mV, 100mV +100°C Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) 250 200 150 100 VOS (µV) 50 0 -50 -40°C +125°C GAIN 100 VSENSE = 2mV, 20mV 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) +100°C +25°C +125°C VOS (µV) -40°C +25°C -100 -150 -200 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 -250 2 VRS+ (V) FIGURE 7. VOS vs VRS+ FIGURE 8. VOS vs VCC, VRS+= 12V 3000 +100°C 2000 1000 VOS (µV) -40°C 0 +25°C GAIN 100 VSENSE = 2mV, 20mV 0.6 0.4 0.2 ACCURACY (%) 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 +100°C -40°C +25°C +125°C +125°C -1000 -2000 -3000 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) -1.4 GAIN 100 VSENSE = 20mV, 100mV 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VRS+ (V) FIGURE 9. VOS vs VCC, VRS+ = 0.1V FIGURE 10. GAIN ACCURACY vs VRS+ = 0V TO 28V 0.6 0.4 0.2 ACCURACY (%) 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 -1.4 0 0.2 0.4 0.6 +125°C +25°C ACCURACY (%) +100°C -40°C GAIN 100 VSENSE = 20mV, 100mV 0.8 1.0 1.2 VRS+ (V) 1.4 1.6 1.8 2.0 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5 +100°C +25°C -40°C +125°C GAIN 100 VSENSE = 2mV, 20mV 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 11. GAIN ACCURACY vs VRS+ = 0V TO 2V FIGURE 12. GAIN ACCURACY vs VCC, VRS+ = 12V 9 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 2 0 -2 ACCURACY (%) -4 -6 -8 -10 -12 -14 -16 -18 -20 2 4 6 8 GAIN 100 VSENSE = 2mV, 20mV +100°C +125°C +25°C -40°C Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) 0.2 VOA PERCENT ACCURACY (%) 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.7 -0.8 -0.9 -1.0 1µ 10µ 100µ IOUT(A) +25°C 1m 10m +100°C -40°C +125°C GAIN 100 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 13. GAIN ACCURACY vs VCC, VRS+ = 0.1V FIGURE 14. NORMALIZED VOA vs IOUT 45 35 GAIN 100 25 GAIN (dB) VRS+= 100mV VRS+ = 12V VOS (µV) 15 5 -5 VCC = 12V -15 V SENSE = 100mV AV = 100 -25 R L = 1M -35 10 100 40 20 0 -20 -40 -60 -80 1k 10k FREQUENCY (Hz) 100k 1M -100 -50 -25 0 25 50 75 TEMPERATURE (°C) 100 125 GAIN 100 VSENSE = 20mV, 100mV VRS+ = 12V FIGURE 15. GAIN vs FREQUENCY VRS+ = 100mV/12V, VSENSE = 100mV, VOUT = 50mVP-P FIGURE 16. VOS (µV) vs TEMPERATURE 0.30 0.25 GAIN ACCURACY (%) 0.20 0.15 0.10 0.05 0 -0.05 -0.10 -50 -25 0 25 GAIN 100 VSENSE = 20mV, 100mV VRS+ = 12V VOUT ERROR (%) -0.5 GAIN 100 -0.6 VRS+ = 12V -0.7 -0.8 -0.9 50 75 100 125 -1 -50 -25 0 TEMPERATURE (°C) 25 50 75 TEMPERATURE (°C) 100 125 FIGURE 17. GAIN ACCURACY (%) vs TEMPERATURE FIGURE 18. VOUT ERROR (%) vs TEMPERATURE 10 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 20 GAIN 50 18 VSENSE = 20mV, 100mV 16 14 Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 -200 -400 GAIN 50 VSENSE = 20mV, 100mV 10 8 6 4 2 0 -250 -200 -150 -100 -50 VOS (µV) 0 50 100 VOS (µV) UNITS 12 +125°C +100°C -40°C 0 2 4 6 8 VRS+ (V) +25°C 10 12 14 16 18 20 22 24 26 28 FIGURE 19. VOS (µV) DISTRIBUTION AT +25°C, VRS+ = 12V, QUANTITY: 100 FIGURE 20. VOS vs VRS+ 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 -200 -400 +125°C GAIN 50 VSENSE = 20mV, 100mV 250 200 150 +100°C GAIN 50 VSENSE = 2mV, 0mV +100°C +25°C -40°C 100 VOS (µV) 50 0 -50 +25°C +125°C VOS (µV) -100 -150 -200 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 -250 2 4 6 -40°C 8 VRS+ (V) 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 21. VOS vs VRS+ FIGURE 22. VOS vs VCC, VRS+ = 12V 3000 2000 1000 VOS (µV) +100°C +25°C 0.6 0.4 0.2 +25°C -40°C -40°C 0 +125°C ACCURACY (%) 0 -0.2 -0.4 -0.6 -0.8 -1.0 GAIN 50 VSENSE = 20mV, 100mV 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VRS+ (V) +100°C +125°C -1000 -2000 -3000 GAIN 50 VSENSE = 2mV, 0mV 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) -1.2 -1.4 FIGURE 23. VOS vs VCC, VRS+ = VRS+ = 0.1V FIGURE 24. GAIN ACCURACY vs VRS+ = 0V TO 28V 11 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 0.6 0.4 0.2 ACCURACY (%) 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 -1.4 0 0.2 +125°C 0.4 0.6 -40°C GAIN 50 VSENSE = 20mV, 100mV 1.4 1.6 1.8 +100°C +25°C Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 +100°C +25°C -40°C ACCURACY (%) +125°C GAIN 50 VSENSE = 2mV, 20mV 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) 0.8 1.0 1.2 VRS+ (V) 2.0 FIGURE 25. GAIN ACCURACY vs VRS+ = 0V TO 2V FIGURE 26. GAIN ACCURACY vs VCC, HIGH-SIDE 2 VOA PERCENT ACCURACY (%) 0 -2 ACCURACY (%) -4 -6 -8 -10 -12 -14 -16 -18 -20 2 4 6 8 +125°C +100°C +25°C -40°C 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.7 -0.8 -0.9 -1.0 1µ 10µ 100µ IOUT(A) -40°C +125°C +100°C +25°C 1m 10m GAIN 50 GAIN 50 VSENSE = 2mV, 20mV 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 27. GAIN ACCURACY vs VCC, LOW-SIDE FIGURE 28. NORMALIZED VOA vs IOUT 45 35 25 GAIN (dB) GAIN 50 -70 -90 -110 VOS (µV) -130 -150 -170 -190 -210 GAIN 50 VSENSE = 20mV, 100mV VRS+ = 12V 15 5 -5 -15 V SENSE = 100mV A = 100 -25 V R L = 1M -35 10 100 VCC = 12V VRS+= 100mV VRS+ = 12V 1k 10k FREQUENCY (Hz) 100k 1M -230 -50 -25 0 25 50 75 TEMPERATURE (°C) 100 125 FIGURE 29. GAIN vs FREQUENCY VRS+ = 100mV/12V, VSENSE = 100mV, VOUT = 50mVP-P FIGURE 30. VOS (µV) vs TEMPERATURE 12 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 0.18 0.17 GAIN ACCURACY (%) 0.16 0.15 0.14 0.13 0.12 0.11 0.1 -50 -25 0 25 50 75 100 GAIN 50 VSENSE = 20mV, 100mV VRS+ = 12V Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) 0.10 0.08 0.06 VOUT ERROR (%) 0.04 0.02 0 -0.02 -0.04 -0.06 -0.08 -0.10 125 -0.12 -50 -25 0 25 50 75 TEMPERATURE (°C) 100 125 GAIN 50 VRS+ = 12V TEMPERATURE (°C) FIGURE 31. GAIN ACCURACY (%) vs TEMPERATURE FIGURE 32. VOUT ERROR (%) vs TEMPERATURE 30 25 20 15 10 5 0 GAIN 20 VSENSE = 20mV, 100mV -250 -200 -150 -100 -50 0 VOS (µV) 50 100 150 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 -200 -400 GAIN 20 VSENSE = 20mV, 100mV VOS (µV) UNITS +125°C +100°C -40°C 0 2 4 6 8 VRS+ (V) +25°C 10 12 14 16 18 20 22 24 26 28 FIGURE 33. VOS (µV) DISTRIBUTION AT +25°C, VRS+ = 12V, QUANTITY: 100 FIGURE 34. VOS vs VRS+ 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 -200 -400 +100°C +125°C GAIN 20 VSENSE = 20mV, 100mV 250 200 150 100 VOS (µV) 50 0 -50 -40°C +25°C +125°C +100°C GAIN 20 VSENSE = 2mV, 20mV VOS (µV) +25°C -40°C -100 -150 -200 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 -250 2 4 6 8 VRS+ (V) 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 35. VOS vs VRS+ FIGURE 36. VOS vs VCC, VRS+ = 12V 13 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 3000 +100°C 2000 1000 VOS (µV) 0 +25°C GAIN 20 VSENSE = 2mV, 20mV Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) 0.6 0.4 0.2 +25°C -40°C -40°C ACCURACY (%) 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 GAIN 20 VSENSE = 20mV, 100mV 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VRS+ (V) +125°C +100°C +125°C -1000 -2000 -3000 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) -1.4 FIGURE 37. VOS vs VCC, VRS+ = 0.1V FIGURE 38. GAIN ACCURACY vs VRS+ = 0V TO 28V 0.6 0.4 0.2 ACCURACY (%) 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 -1.4 0 0.2 0.4 +125°C 0.6 -40°C +100°C +25°C GAIN 20 VSENSE = 20mV, 100mV ACCURACY (%) 0.8 1.0 1.2 VRS+ (V) 1.4 1.6 1.8 2.0 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 GAIN 20 VSENSE = 2mV, 20mV +100°C +25°C -40°C +125°C 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 39. GAIN ACCURACY vs VRS+ = 0V TO 2V FIGURE 40. GAIN ACCURACY vs VCC, HIGH-SIDE 2 VOA PERCENT ACCURACY (%) 0 -2 ACCURACY (%) -4 -6 -8 -10 -12 -14 -16 -18 -20 2 4 6 8 +125°C +100°C +25°C -40°C 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.7 -0.8 -0.9 -1.0 1µ 10µ 100µ IOUT(A) +25°C +125°C +100°C -40°C 1m 10m GAIN 20 GAIN 20 VSENSE = 2mV, 20mV 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 41. GAIN ACCURACY vs VCC, LOW-SIDE FIGURE 42. NORMALIZED VOA vs IOUT 14 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 45 35 25 GAIN (dB) VRS+ = 100mV VRS+ = 12V GAIN 20 Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) -20 -40 -60 VOS (µV) -80 -100 -120 -140 -50 GAIN 20 VSENSE = 20mV, 100mV VRS+ = 12V 15 5 -5 -15 V SENSE = 100mV A = 100 -25 V R L = 1M -35 10 100 VCC = 12V 1k 10k FREQUENCY (Hz) 100k 1M -25 0 25 50 75 TEMPERATURE (°C) 100 125 FIGURE 43. GAIN vs FREQUENCY VRS+ = 100mV/12V, VSENSE = 100mV, VOUT = 50mVP-P FIGURE 44. VOS (µV) vs TEMPERATURE 0.330 0.325 GAIN ACCURACY (%) 0.320 0.3150 0.310 0.305 0.300 0.295 0.290 -50 -25 0 25 GAIN 20 VSENSE = 20mV, 100mV VRS+ = 12V VOUT ERROR (%) 0.31 0.29 0.27 0.25 0.23 0.21 0.19 0.17 GAIN 20 VRS+ = 12V 50 75 100 125 0.15 -50 -25 0 TEMPERATURE (°C) 25 50 75 TEMPERATURE (°C) 100 125 FIGURE 45. GAIN ACCURACY (%) vs TEMPERATURE FIGURE 46. VOUT ERROR (%) vs TEMPERATURE 26 GAIN 101 ADJ 24 Rf = 100k, Rg = 1k 22 VSENSE = 20mV, 100mV 20 18 16 14 12 10 8 6 4 2 0 -200 -160 -120 -80 -40 0 40 VOS (µV) 80 120 160 200 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 -200 -400 GAIN 101 ADJ Rf = 100k, Rg = 1k VSENSE = 20mV, 100mV VOS (µV) UNITS +125°C +100°C -40°C 0 2 4 6 8 VRS+ (V) +25°C 10 12 14 16 18 20 22 24 26 28 FIGURE 47. VOS (µV) DISTRIBUTION AT +25°C, VRS+ = 12V, QUANTITY: 100 FIGURE 48. VOS vs VRS+ 15 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 -200 -400 Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) 250 200 150 100 VOS (µV) 50 0 -50 -40°C +25°C GAIN 101 ADJ Rf = 100k, Rg = 1k VSENSE = 2mV, 20mV +100°C GAIN 101 ADJ Rf = 100k, Rg = 1k VSENSE = 20mV, 100mV +125°C VOS (µV) -40°C +25°C +100°C -100 -150 -200 +125°C 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 -250 2 VRS+ (V) FIGURE 49. VOS vs VRS+ FIGURE 50. VOS vs VCC, HIGH-SIDE 3000 2000 1000 VOS (µV) +100°C +25°C GAIN 101 ADJ Rf = 100k, Rg = 1k VSENSE = 2mV, 20mV ACCURACY (%) 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 +25°C +100°C +125°C GAIN 101 ADJ Rf = 100k, Rg = 1k VSENSE = 20mV, 100mV -40°C 0 +125°C -40°C -1000 -2000 -3000 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) -1.4 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VRS+ (V) FIGURE 51. VOS vs VCC, LOW-SIDE FIGURE 52. GAIN ACCURACY vs VRS+ = 0V TO 28V 0.6 0.4 0.2 ACCURACY (%) 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 -1.4 0 0.2 0.4 0.6 +25°C -40°C +100°C +125°C GAIN 101 ADJ Rf = 100k, Rg = 1k VSENSE = 20mV, 100mV ACCURACY (%) 0.8 1.0 1.2 VRS+ (V) 1.4 1.6 1.8 2.0 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 -40°C +100°C +25°C GAIN 101 ADJ Rf = 100k, Rg = 1k VSENSE = 2mV, 20mV +125°C 2 4 6 8 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 53. GAIN ACCURACY vs VRS+ = 0V TO 2V FIGURE 54. GAIN ACCURACY vs VCC, VRS+ = 12V 16 FN6548.3 May 27, 2010 ISL28006 Typical Performance Curves 2 0 -2 ACCURACY (%) -4 -6 -8 -10 -12 -14 -16 -18 -20 2 4 6 8 GAIN 101 ADJ Rf = 100k, Rg = 1k VSENSE = 2mV, 20mV +125°C Vcc = 12V, RL = 1M, unless otherwise specified. (Continued) 0.2 0.0 VOA PERCENT ACCURACY (%) -0.2 -0.4 -0.6 GAIN 101 ADJ R = 100k -0.8 Rf = 1k g -1.0 0.2 0.0 -0.2 -0.4 -0.6 GAIN 21 ADJ -0.8 Rf = 100k R = 5k -1.0 g 1µ 10µ +25°C -40°C +100°C +125°C +25°C -40°C +100°C +125°C 100µ IOUT(A) 1m 10m +100°C +25°C -40°C 10 12 14 16 18 20 22 24 26 28 VCC (V) FIGURE 55. GAIN ACCURACY vs VCC, VRS+ = 0.1V FIGURE 56. NORMALIZED VOA vs IOUT 45 40 35 30 GAIN (dB) 25 20 VRS+ = 0.1V GAIN = 21 VCC = 12V 15 VSENSE = 100mV VRS+ = 0.1V GAIN = 101 VRS+ = 12V GAIN = 51 VRS+ = 12V GAIN = 101 200 150 100 50 VOS (µV) 0 -50 -100 -150 -200 -250 -300 -350 -50 GAIN = 21 GAIN = 101 VSENSE = 20mV, 100mV VRS+ = 12V GAIN = 21, 101 Rf = 100k Rg = 1k, 5k RL = 1M VRS+ = 12V GAIN = 21 10 GAIN = 21, 51, 101 Rf = 100k 5 Rg = 1k, 2k, 5k VRS+ = 12V GAIN = 51 RL = 1M 0 100 1k 10k 100k FREQUENCY (Hz) 1M -25 0 25 50 75 TEMPERATURE (°C) 100 125 FIGURE 57. GAIN vs FREQUENCY VRS+ = 100mV/12V, VSENSE = 100mV, VOUT = 50mVP-P FIGURE 58. VOS (µV) vs TEMPERATURE 0.40 0.35 GAIN = 101 GAIN ACCURACY (%) VOUT ERROR (%) 0.30 0.25 0.20 0.15 VSENSE = 20mV, 100mV VRS+ = 12V GAIN = 21 0.6 0.5 0.4 0.3 0.2 0.1 VSENSE = 20mV, 100mV VRS+ = 12V GAIN = 21 GAIN = 101 0.10 GAIN = 21, 101 Rf = 100k 0.05 Rg = 1k, 5k RL = 1M 0 -50 -25 0 25 50 75 100 125 0 GAIN = 21, 101 Rf = 100k -0.1 Rg = 1k, 5k RL = 1M -0.2 -50 -25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) FIGURE 59. GAIN ACCURACY (%) vs TEMPERATURE FIGURE 60. VOUT ERROR (%) vs TEMPERATURE 17 FN6548.3 May 27, 2010 ISL28006 Test Circuits and Waveforms VCC VR1 R1 + + VRS+ VSENSE GND 1MΩ RL VOUT RS+ RSOUT + + VRS+ VSENSE R2 VR2 RS+ RSGND 1MΩ RL VOUT OUT VCC FIGURE 61. IS, VOS, VOA, CMRR, PSRR, GAIN ACCURACY VCC RS+ VRS+ VRSPULSE GENERATOR RSGND 1MΩ RL VOUT FIGURE 62. INPUT BIAS CURRENT, LEAKAGE CURRENT SIGNAL GENERATOR VCC RS+ OUT VRS+ VSENSE OUT GND 1MΩ RL VOUT RS- FIGURE 63. ts, SATURATION RECOVERY TIME VCC RS+ VRS+ RS- FIGURE 64. GAIN vs FREQUENCY OUT GND 1MΩ RL VOUT PULSE GENERATOR FIGURE 65. SLEW RATE Applications Information Functional Description The ISL28006-20, ISL28006-50 and ISL28006-100 are single supply, uni-directional current sense amplifiers with fixed gains of 20V/V, 50V/V and 100V/V respectively. The ISL28006-ADJ is single supply, uni-directional current sense amplifier with an adjustable gain via external resistors (see Figure 70). The ISL28006-ADJ is stable for gains of 20 and higher. The ISL28006 is a 2-stage amplifier. Figure 66 shows the active circuitry for high-side current sense applications where the sense voltage is between 1.35V to 28V. Figure 67 shows the active circuitry for ground sense applications where the sense voltage is between 0V to 1.35V. The first stage is a bi-level trans-conductance amp and level translator. The gm stage converts the low voltage drop (VSENSE) sensed across an external milli-ohm sense resistor, to a current (@ gm = 21.3µA/V). The trans-conductance amplifier forces a current through R1 18 resulting to a voltage drop across R1 that is equal to the sense voltage (VSENSE). The current through R1 is mirrored across R5 creating a ground-referenced voltage at the input of the second amplifier equal to VSENSE. The second stage is responsible for the overall gain and frequency response performance of the device. The fixed gains (20, 50, 100) are set with internal resistors Rf and Rg. The variable gain (ADJ) has an additional FB pin and uses external gain resistors to set the gain of the output. For the fixed gain amps the only external component needed is a current sense resistor (typically 0.001Ω to 0.01Ω, 1W to 2W). The transfer function for the fixed gain parts is given in Equation 1. V OUT = GAIN × ( I S R S + V OS ) (EQ. 1) The transfer function for the adjustable gain part is given in Equation 2. RF ⎞ ⎛ V OUT = ⎜ 1 + ------- ⎟ ( I S R S + V OS ) R G⎠ ⎝ (EQ. 2) FN6548.3 May 27, 2010 ISL28006 The input gm stage derives its ~2.86µA supply current from the input source through the RS+ terminal as long as the sensed voltage at the RS+ pin is >1.35V and the gmHI amplifier is selected. When the sense voltage at RS+ drops below the 1.35V threshold, the gmLO amplifier kicks in and the gmLO output current reverses, flowing out of the RS- pin. VCC OPTIONAL FILTER CAPACITOR I = 2.86µA VSENSE RS+ IS HIGH-SIDE SENSING VRS+ = 2V TO 28V VCC = 2V to 28V R2 OPTIONAL TRANSIENT PROTECTION + - RS VSENSE RS- R1 gmHI + OUT Rf FB gmLO ‘VSENSE R5 Rg ADJ OPTION ONLY 1.35V R3 LOAD R4 IMIRROR GND FIGURE 66. HIGH-SIDE CURRENT DETECTION VCC OPTIONAL FILTER CAPACITOR I = 2.86µA VSENSE RS+ IS + RSR2 + OPTIONAL TRANSIENT PROTECTION 1.35V R3 VCC OUT Rf FB gmLO R5 ‘VSENSE GND Rg ADJ OPTION ONLY RS VSENSE R1 gmHI LOW-SIDE SENSING VRS+= 0V TO 2V VCC = 2V TO 28V LOAD R4 IMIRROR FIGURE 67. LOW-SIDE CURRENT DETECTION 19 FN6548.3 May 27, 2010 ISL28006 Hysteretic Comparator The input trans-conductance amps are under control of a hysteretic comparator operating from the incoming source voltage on the RS+ pin (Figure 66). The comparator monitors the voltage on RS+ and switches the sense amplifier from the low-side gm amp to the high-side gm amplifier whenever the input voltage at RS+ increases above the 1.35V threshold. Conversely, a decreasing voltage on the RS+ pin, causes the hysteric comparator to switch from the high-side gm amp to the low-side gm amp as the voltage decreases below 1.35V. It is that low-side sense gm amplifier that gives the ISL28006 the proprietary ability to sense current all the way to 0V. Negative voltages on the RS+ or RS- are beyond the sensing voltage range of this amplifier. 0.5 0.4 0.3 ACCURACY (%) 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 0 0.2 0.4 0.6 0.8 1.0 1.2 VRS+ (V) 1.4 1.6 1.8 2.0 protection for a 2V transient with the maximum of 20mA flowing through the input while adding only an additional 13µV (worse case over-temperature) of VOS. Refer to Equation 3: ( ( R P × I RS- ) = ( 100 Ω × 130nA ) = 13 μ V ) (EQ. 3) Switching applications can generate voltage spikes that can overdrive the amplifier input and drive the output of the amplifier into the rails, resulting in a long overload recover time. Capacitors CM and CD filter the common mode and differential voltage spikes. Error Sources There are 3 dominant error sources: gain error, input offset voltage error and Kelvin voltage error (see Figure 69). The gain error is dominated by the internal resistance matching tolerances. The remaining errors appear as sense voltage errors at the input to the amplifier. They are VOS of the amplifier and Kelvin voltage errors. If the transient protection resistor is added, an additional VOS error can result from the IxR voltage due to input bias current. The limiting resistor should only be added to the RS- input, due to the high-side gm amplifier (gmHI) sinking several micro amps of current through the RS+ pin. Layout Guidelines The Kelvin Connected Sense Resistor The source of Kelvin voltage errors is illustrated in Figure 69. The resistance of 1/2 Oz copper is ~1mΩ per square with a TC of ~3900ppm/°C (0.39%/°C). When you compare this unwanted parasitic resistance with the total 1mΩ to 10mΩ resistance of the sense resistor, it is easy to see why the sense connection must be chosen very carefully. For example, consider a maximum current of 20A through a 0.005Ω sense resistor, generating a VSENSE = 0.1 and a full scale output voltage of 10V (G = 100). Two side contacts of only 0.25 square per contact puts the VSENSE input about 0.5 x 1mΩ away from the resistor end capacitor. If only 10A the 20A total current flows through the kelvin path to the resistor, you get an error voltage of 10mV (10A x 0.5sq x 0.001Ω/sq. = 10mV) added to the 100mV sense voltage for a sense voltage error of 10% (0.110V-0.1)/0.1V)x 100. Copper Trace 1/2 Oz COPPER TRACE 1mΩ /SQ 30mO/Sq. CURRENT OUT FIGURE 68. GAIN ACCURACY vs VRS+ = 0V TO 2V Typical Application Circuit Figure 70 shows the basic application circuit and optional protection components for switched-load applications. For applications where the load and the power source is permanently connected, only an external sense resistor is needed. For applications where fast transients are caused by hot plugging the source or load, external protection components may be needed. The external current limiting resistor (RP) in Figure 70 may be required to limit the peak current through the internal ESD diodes to