High-Side Current Sensor

FAN4010 High-Side Current Sensor March 2007 FAN4010 High-Side Current Sensor Features at +5V ■ Low cost, accurate, high-side current sensing ■ Output voltage scaling ■ Up to 2.5V sense voltage ■ 2V to 6V supply range ■ 2μA typical offset current ■ 3.5μA quiescent current ■ -0.2% accuracy ■ SOT23-5 package ■ 6-lead MicroPak™ future package option Description The FAN4010 is a high-side current sense amplifier designed for battery-powered systems. Using the FAN4010 for high-side power-line monitoring does not interfere with the battery charger’s ground path. The FAN4010 is designed for portable PC’s, cellular phones, and other portable systems where battery/DC power-line monitoring is critical. To provide a high level of flexibility, the FAN4010 functions with an external sense resistor to set the range of load current to be monitored. It has a current output that can be converted to a ground-referred voltage with a single resistor, accommodating a wide range of battery voltages and currents. The FAN4010 features allow it to be used for gas gauging as well as uni-directional or bi-directional current monitoring. Applications ■ Battery chargers ■ Smart battery packs ■ DC motor control ■ Over-current monitor ■ Power management ■ Programmable current source www.DataSheet4U.com Functional Block Diagram and Typical Circuit VIN 100 1 2 3 NC Load Load RLoad 5 GND RSENSE VIN IOUT 4 VIN VOUT ROUT IOUT Figure 1. Functional Block Diagram and Typical Circuit Ordering Information Part Number FAN4010IS5X FAN4010IL6X* Package SOT23-5 MicroPak-6 Pb-Free Yes Yes Operating Temperature Range -40°C to +85°C -40°C to +85°C Packaging Method Reel Reel Moisture sensitivity level for all parts is MSL-1. MicroPak™ is a trademark of Fairchild Semiconductor Corporation. *Future package option. © 2007 Fairchild Semiconductor Corporation FAN4010 Rev. 1.0.1 www.fairchildsemi.com FAN4010 High-Side Current Sensor Pin Configurations MicroPak SOT23-5 NC GND IOUT 1 2 3 4 5 Load GND NC 1 2 3 6 5 4 Load VIN IOUT VIN NC top view Figure 2. SOT23-5 Pin Configuration Figure 3. MicroPak™-5 Pin Configuration Pin Assignments SOT Pin # 1 2 3 4 5 MicroPak™ Pin # 2, 3 1 4 5 6 Name NC GND IOUT VIN Load Description No Connect; leave pin floating Ground Output current, proportional to VIN - VLoad Input voltage (supply voltage) Connection to load or battery © 2007 Fairchild Semiconductor Corporation FAN4010 Rev. 1.0.1 www.fairchildsemi.com 2 FAN4010 High-Side Current Sensor Absolute Maximum Ratings Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbol Vs VIN Supply Voltage Input Voltage Range Parameter Min. 0 0 Max. 6.3 6.3 Unit V V Reliability Information Symbol TJ TSTG TL θJA Parameter Junction Temperature Storage Temperature Range Reflow Temperature (Soldering) Package Thermal Resistance MicroPak™-5 SOC23-5 Min. -65 Typ. Max. 150 150 260 Unit °C °C °C °C/W °C/W 271 191 Note: 1. Package thermal resistance (θJA), JEDEC standard, multi-layer test boards, still air. ESD Protection Symbol HBM CDM Electrostatic Discharge Standard Human Body Model Charged Device Model Value 5kV 1kV Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to absolute maximum ratings. Symbol TA Vs VIN VSENSE Parameter Operating Temperature Range Supply Voltage Range Input Voltage Range Sensor Voltage Range, VSENSE = VIN - VLoad; ROUT = 0Ω Min. -40 2 2 0 Typ. Max. +85 6 6 2.5 Unit °C V V V © 2007 Fairchild Semiconductor Corporation FAN4010 Rev. 1.0.1 www.fairchildsemi.com 3 FAN4010 High-Side Current Sensor Electrical Characteristics at +5V TA = 25°C, Vs = VIN = 5V, ROUT = 100Ω, RSENSE = 100Ω, unless otherwise noted. Symbol BWss BWLs VIN Parameter Small Signal Bandwidth Large Signal Bandwidth Input Voltage Range Conditions PIN = -40dBm(2), VSENSE = 10mV PIN = -20dBm(3), VSENSE = 100mV VIN = Vs VSENSE = 0V VSENSE = 10mV Min. Typ. 600 2 Max. Units kHz MHz Frequency Domain Response 2 0 93 0.975 1.95 9.7 1 100 1.000 2.00 10.0 3.5 2 6 4 107 1.025 2.05 10.3 5.0 V μA μA mA mA mA μA nA IOUT Output Current (1,4) VSENSE = 100mV VSENSE = 200mV VSENSE = 1V Is ISENSE ACY Gm Supply Current (1) VSENSE = 0V, GND pin current Load Pin Input Current Accuracy Transconductance RSENSE = 100Ω, RSENSE = 200mV(1) IOUT /VSENSE -2.5 -0.2 10000 2.5 % μA/V Notes: 1. 100% tested at 25˚C. 2. -40dBm = 6.3mVpp into 50Ω. 3. -20dBm = 63mVpp into 50Ω. 4. Includes input offset voltage contribution. © 2007 Fairchild Semiconductor Corporation FAN4010 Rev. 1.0.1 www.fairchildsemi.com 4 FAN4010 High-Side Current Sensor Typical Performance Characteristics TA = 25°C, Vs = VIN = 5V, ROUT = 100Ω, RSENSE = 100Ω, unless otherwise noted. 10 250 VS = 5V Output Current Error (%) 200 150 100 50 0 -50 VIN = 5V ROUT = 0Ω Average of 100 parts IOUT (mA) ROUT = 0Ω ROUT = 100Ω +1 SIGMA Average 1 -1 SIGMA -100 -150 0.1m 1m 10m 100m 1 10 0.1 0.01 0.1 1 VSENSE (V) VSENSE (V) Figure 4. VSENSE vs. Output Current Figure 5. Output Current Error vs. VSENSE 10.4 10.2 Normalized Gain (dB) VSENSE = 1V VIN = 5V RL= 0Ω 3 0 -3 -6 -9 Vs = 5V ROUT = 100Ω VSENSE = 1V IOUT (mA) 10.0 9.8 9.6 9.4 -40 -20 0 20 40 60 80 VSENSE = 0.1V VSENSE = 0.01V -12 PIN = -20dBm of VSENSE = 0.1V & 1V PIN = -40dBm of VSENSE = 0.01V 0.01 0.1 1 10 Temperature (°C) Frequency (MHz) Figure 6. Output Current vs. Temperature Figure7. Frequency Response 12 ROUT = 0Ω 12 VSENSE = 1V VSENSE = 0.8V VSENSE = 0.6V VSENSE = 0.4V VSENSE = 0.2V ROUT = 100Ω 10 8 10 8 VSENSE = 1V VSENSE = 0.8V VSENSE = 0.6V VSENSE = 0.4V VSENSE = 0.2V IOUT (mA) 6 4 2 0 -2 0 1 2 IOUT (mA) 5 6 4 2 0 -2 3 4 0 1 2 3 4 5 VIN (V) VIN (V) Figure 8. Transfer Characteristics Figure 9. Transfer Characteristics © 2007 Fairchild Semiconductor Corporation FAN4010 Rev. 1.0.1 www.fairchildsemi.com 5 FAN4010 High-Side Current Sensor Typical Performance Characteristics (Continued) TA = 25°C, Vs = VIN = 5V, ROUT = 100Ω, RSENSE = 100Ω, unless otherwise noted. 0 2.5 VIN = 5V PIN = -20dBm ROUT = 100Ω VSENSE = 200mV ROUT = 0Ω Average of 100 parts +1 SIGMA Average Output Current Error (%) -10 -20 2.0 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.5 2.0 CMRR (dB) -30 -40 -50 -60 -70 -80 -90 0.00001 0.0001 0.001 0.01 0.1 1 10 VSENSE = 100mV -1 SIGMA VSENSE = 10mV VSENSE = 1mV 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Frequency (MHz) VIN (V) Figure 10. CMRR vs. Frequency Figure 11. VIN vs. Output Current Error 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 VIN = 5V ROUT = 100Ω Is (μA) VSENSE (V) Figure 12. Supply Current vs. VSENSE © 2007 Fairchild Semiconductor Corporation FAN4010 Rev. 1.0.1 www.fairchildsemi.com 6 FAN4010 High-Side Current Sensor Application Information Detailed Description The FAN4010 measures the voltage drop (V SENSE) across an external sense resistor located in the high voltage side of the circuit. V SENSE is converted to a linear current via an internal operational amplifier and precision 100Ω resistor. The value of this current is V SENSE/100Ω (internal). Output current flows from the IOUT pin to an external resistor R OUT to generate an output voltage proportional to the current flowing to the load. Use the following equations to scale a load current to an output voltage: VSENSE = ILoad * R SENSE V OUT = 0.01 x VSENSE x ROUT RLoad 1 2 3 NC Load to compensate for this effect. Additionally, self heating due to load currents introduces a nonlinearity error. Care must be taken not to exceed the maximum power dissipation of the copper trace. INPUT RSENSE 0.1in Copper LOAD 0.3in Copper 0.3in Copper 1 2 3 NC GND IOUT Load 5 VIN 4 EQ.1 EQ.2 VOUT ROUT 5 Figure 14. Using PCB Trace for RSENSE – GND RSENSE 100 VIN VSENSE Selecting ROUT R OUT can be chosen to obtain the output voltage range required for the particular downstream application. For example, if the output of the FAN4010 is intended to drive an analog-to-digital convertor (ADC), R OUT should be chosen such that the expected full-scale output current produces an input voltage that matches the input range of the ADC. For instance, if expected loading current ranges from 0 to 1A, a R SENSE resistor of 1Ω produces an output current that ranges from 0 to 10mA. If the input voltage range of the ADC is 0 to 2V, a R OUT value of 200Ω should be used. The input voltage and full-scale output current (IOUT_ needs to be taken into account when setting up the output range. To ensure sufficient operating headroom, choose: FS) + 4 IOUT VIN VOUT ROUT Figure 13. Functional Circuit Selecting RSENSE Selection of RSENSE is a balance between desired accuracy and allowable voltage loss. Although the FAN4010 is optimized for high accuracy with low VSENSE values, a larger RSENSE value provides additional accuracy. However, larger values of RSENSE create a larger voltage drop, reducing the effective voltage available to the load. This can be troublesome in low-voltage applications. Because of this, the maximum expected load current and allowable load voltage should be well understood. Although higher values of VSENSE can be used, RSENSE should be chosen to satisfy the following condition: 10mV < VSENSE < 200mV EQ. 3 (R OUT * IOUT_FS) such that VIN - VSENSE - (ROUT * IOUT_FS) > 1.2V EQ. 4 For