MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output 10V I 4.5V TO 76V LOAD V I SENSE CHARGE CHARGE CURRENT SYSTEM LOAD BATTERY REF R AND CHARGER - V SENSE V 5V OUT = 10V RS- RS+ V OUT VCC VSENSE MAX4081T REF1A -250mV 250mV 5V REF1B VOUT = VGND -5V VREF1A = VREF1B = 5V GND OUT DISCHARGE CURRENT Figure 1. MAX4081T OUT Transfer Curve VSENSE VSENSE I RS+ RS- LOAD RSENSE RS+ RS- RG1 RG2 MAX4081 RG1 RG2 RF A1 MAX4080 A1 Q1 Q2 A2 OUT Q1 125kΩ CURRENT CURRENT REF1B MIRROR MIRROR I 125kΩ CURRENT A2 OUT A2 A3 REF1A MIRROR VREF GND Figure 2. MAX4080 Functional Diagram Figure 3. MAX4081 Functional Diagram that swings above VREF voltage for positive-sense volt- Note: For Gain = 5 (F), RG1 = RG2 = 160k. ages and below VREF for negative-sense voltages. For Gain = 20 (T), RG1 = RG2 = 60k. VOUT is equal to VREF when VSENSE is equal to zero. For Gain = 60 (S), RG1 = RG2 = 20k. Set the full-scale output range by selecting RSENSE and the appropriate gain version of the MAX4080/ MAX4081. www.maximintegrated.com Maxim Integrated │ 10