Data SheetAD8451TYPICAL PERFORMANCE CHARACTERISTICS AVCC = +15 V, AVEE = −15 V, TA = 25°C, and RL = ∞, unless otherwise noted. IA CHARACTERISTICS302025E (V)15G AE (V)LT20G10A LTE VO D155E VO-MODN100-MO NMMO O5–5CMMOTO CPU0T –10INPU IN−5–15AVCC = +15VAVCC = +25VAVEE = –15VAVEE = −5V−10–20−10−5 003 –20–15–10–505101520051015202530 006 OUTPUT VOLTAGE (V)OUTPUT VOLTAGE (V) 12137- 12137- Figure 3. Input Common-Mode Voltage vs. Output Voltage Figure 6. Input Common-Mode Voltage vs. Output Voltage for AVCC = +25 V and AVEE = −5 V for AVCC = +15 V and AVEE = −15 V 1515AVCC = +15V AVEE = –15V1010)55mA)(mA(T NNTE00CURRCURRET U–5UTP–5ININP–10–10AVCC = +25V AVEE = –5V–15–15–35 –30 –25 –20 –15 –10 –50510 15 20 25 30 35 40 45 004 –45–40–35–30–25–20–15–10 –5 05 10 15 20 25 30 35 40 45 007 INPUT VOLTAGE (V) 12137- INPUT VOLTAGE (V) 12137- Figure 4. Input Overvoltage Performance Figure 7. Input Overvoltage Performance for AVCC = +25 V and AVEE = −5 V for AVCC = +15 V and AVEE = −15 V 17.02016.81916.6A)A)18n ( 16.4n (NTNT16.2AVCC = +15V17AVEE = –15V+IB16.0CURRE16CURREASAVCC = +25V–I15.8ASBBIAVEE = –5V15BIUT 15.6UTINP14INP15.41315.215.012–15–10–50510152025 005 –40 –30 –20 –100102030405060708090 008 INPUT COMMON-MODE VOLTAGE (V) 12137- TEMPERATURE (°C) 12137- Figure 5. Input Bias Current vs. Input Common-Mode Voltage Figure 8. Input Bias Current vs. Temperature Rev. 0 | Page 9 of 32 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS IA CHARACTERISTICS DA CHARACTERISTICS CC AND CV LOOP FILTER AMPLIFIERS, AND VSET BUFFER VINT BUFFER REFERENCE CHARACTERISTICS THEORY OF OPERATION OVERVIEW INSTRUMENTATION AMPLIFIER (IA) Reversing Polarity When Charging and Discharging IA Offset Option Battery Reversal and Overvoltage Protection DIFFERENCE AMPLIFIER (DA) CC AND CV LOOP FILTER AMPLIFIERS Compensation VINT Buffer MODE PIN, CHARGE AND DISCHARGE CONTROL APPLICATIONS INFORMATION FUNCTIONAL DESCRIPTION POWER SUPPLY CONNECTIONS CURRENT SENSE IA CONNECTIONS Current Sensors Optional Low-Pass Filter VOLTAGE SENSE DA CONNECTIONS Reverse Battery Conditions BATTERY CURRENT AND VOLTAGE CONTROL INPUTS (ISET AND VSET) LOOP FILTER AMPLIFIERS CONNECTING TO A PWM CONTROLLER (VCTRL PIN) STEP-BY-STEP DESIGN EXAMPLE Step 1: Design the Switching Power Converter Step 2: Identify the Control Voltage Range of the ADP1972 Step 3: Determine the Control Voltage for the CV Loop Step 4: Determine the Control Voltage for the CC Loop and the Shunt Resistor Step 5: Choose the Control Voltage Sources Step 6: Select the Compensation Devices EVALUATION BOARD INTRODUCTION FEATURES AND TESTS EVALUATING THE AD8451 Test the Instrumentation Amplifier 20 mV Offset at IMEAS Output Test the Difference Amplifier 5 mV Offset at BVMEAS Output CC and CV Integrator Tests Loop Compensation SCHEMATIC AND ARTWORK OUTLINE DIMENSIONS ORDERING GUIDE