ZXCT1011 High-side low drift current monitor Description The ZXCT1011 is a high side current sense monitor. Using this type of device eliminates the need to disrupt the ground plane when sensing a load current. The ZXCT1011 takes the voltage developed across a current shunt resistor and translates it into a proportional output current. A user defined output resistor scales the output current into a ground referenced voltage. A current reference resistor, external to the IC, results in an improved temperature coefficient compared to the ZXCT1009. The wide input voltage range of 20V down to as low as 2.5V make it suitable for a range of applications. With a minimum operating current of just 4uA, combined with its SOT23-5 package make it suitable for portable battery equipment too. Features Applications Accurate high-side current sensing Automotive current measurement 2.5V to 20V supply range Battery management 4 A quiescent current DC motor and solenoid control 1% typical accuracy Over current monitor Package SOT23-5 Power management Temperature range -40 to 125C Typical application circuit Pin connections R sense Load Vin N/C V sense+ 5 4 R shunt V V sense+ sense- I out 120 ZXCT1011 3 R V shunt sense- I out 2 V Rout GND Ordering information Order code Pack Part Reel Size Tape width Quantity Per mark inches (mm) reel ZXCT1011E5TA SOT23-5 1011 7 (180) 8mm 3,000 Issue 1- July 2005 1 www.zetex.com Zetex Semiconductors plc 2005ZXCT1011 Absolute maximum ratings V 20 V sense+ Voltage on any pin 0.6V and V +0.5V sense+ V to V 2.5V sense+ sense- Operating temperature -40 to 125C Storage temperature -55 to 150C Maximum junction temperature 150C Package power dissipation 300mW at T = 25C (De-rate to zero at 150C) A Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for extended periods, may reduce device reliability. Electrical characteristics Test conditions T = 25C, V = 5V, R = 120 . V =100mV. Unless otherwise stated. A in shunt sense Symbol Parameter Conditions Min Typ. Max Units * Supply range - 2.5 - 20 V V in I Output current V = 0V 1 4 15 A out sense 84 116 124 A =10mV 273 320 330 A =30mV 0.97 1.00 1.03 mA =100mV 1.95 2.00 2.05 mA =200mV 4.85 5.00 5.15 mA =500mV V - 0 - 500 mV sense Sense voltage I V input current - - - 100 nA sense - sense- Acc Accuracy R = 0.1 -3 - 3 % sense V = 100mV sense g Transconductance R = 120 -10 - mA/V m shunt I /V out sense Tc - - 30 150 ppm/ C Temperature coefficient ** Bandwidth V = 10mV -400 -kHz BW sense CL = 5pF, R = 1k out 1.5 MHz V = 100mV sense CL = 5pF, R = 1k out PSSR Supply rejection V = 200mV, R =1k -68 - dB sense out NOTES: *V relative to I . sense+ out V = (V ) - (V ). sense sense+ sense- Temperature dependent measurements are extracted from characterization and simulation results. ** Where CL is the capacitance across R . out Issue 1- July 2005 2 www.zetex.com Zetex Semiconductors plc 2005