STEVAL-ISQ014V1 STMicroelectronics

STEVAL-ISQ014V1 Low-side current sensing evaluation board based on the TSZ121 op amp Data brief Description The STEVAL-ISQ014V1 product evaluation board implements low-side current sensing which consists in placing a sense resistor between the load and the circuit ground. The resulting voltage drop is amplified using a TSZ121 op amp. The common mode voltage is close to ground, whatever the voltage of the power source, so the current sense voltage can be amplified by this low voltage op amp without restriction. The circuit offers very stable electrical characteristics over the entire supply voltage range and is particularly suited for automotive and industrial applications. Features Thanks to the highly accurate TSZ121 op amp, Very high accuracy: offset voltage 5 V max at precise current measurements can be made 25 C, 8 V over full temperature range (-40 C through your application without the added cost of to 125 C) high-precision resistors. Rail-to-rail input and output Low supply voltage: 1.8 - 5.5 V Low power consumption: 40 A max. at 5 V Gain bandwidth product: 400 kHz High tolerance to ESD: 4 kV HBM Extended temperature range: -40 to +125 C Micro-packages: SC70-5 (TSZ121), DFN8 2x2 (TSZ122), and QFN16 3x3 (TSZ124) RoHS compliant May 2014 DocID026324 Rev 1 1/4 For further information contact your local STMicroelectronics sales office. www.st.comSchematic diagram STEVAL-ISQ014V1 1 Schematic diagram Figure 1. STEVAL-ISQ014V1 circuit schematic In C1 Vccp Vccp Vcc 22nF Rg2 3 TSZ121ILT 100 Vout V+ Vccn 1 GND 4 V- Vccn Rg1 Rf1 100 47k Out Cf 33nF 2/4 DocID026324 Rev 1 Rsh 30m Rf2 47k 2 6