Datasheet ADP1870, ADP1871 (Analog Devices) - 2
| Manufacturer | Analog Devices |
| Description | Synchronous Buck Controller with Constant On-Time and Valley Current Mode |
| Pages / Page | 44 / 2 — ADP1870/ADP1871. Data Sheet. TABLE OF CONTENTS. REVISION HISTORY … |
| Revision | B |
| File Format / Size | PDF / 1.8 Mb |
| Document Language | English |
ADP1870/ADP1871. Data Sheet. TABLE OF CONTENTS. REVISION HISTORY 7/12—Rev. A to Rev. B. 6/10—Rev. 0 to Rev. A
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ADP1870/ADP1871 Data Sheet TABLE OF CONTENTS
Features .. 1 Power Saving Mode (PSM) Version (ADP1871).. 22 Applications ... 1 Timer Operation .. 22 General Description ... 1 Pseudo-Fixed Frequency ... 23 Typical Applications Circuit .. 1 Applications Information .. 24 Revision History ... 2 Feedback Resistor Divider .. 24 Specifications ... 3 Inductor Selection .. 24 Absolute Maximum Ratings .. 5 Output Ripple Voltage (ΔVRR) .. 24 Thermal Resistance .. 5 Output Capacitor Selection... 24 Boundary Condition .. 5 Compensation Network .. 25 ESD Caution .. 5 Efficiency Considerations ... 26 Pin Configuration and Function Descriptions ... 6 Input Capacitor Selection .. 27 Typical Performance Characteristics ... 7 Thermal Considerations .. 28 ADP1870/ADP1871 Block Diagram .. 18 Design Example .. 29 Theory of Operation .. 19 External Component Recommendations .. 31 Startup .. 19 Layout Considerations ... 33 Soft Start .. 19 IC Section (Left Side of Evaluation Board) ... 37 Precision Enable Circuitry .. 19 Power Section ... 37 Undervoltage Lockout ... 19 Differential Sensing .. 38 On-Board Low Dropout Regulator .. 19 Typical Applications Circuits .. 39 Thermal Shutdown ... 20 15 A, 300 kHz High Current Application Circuit .. 39 Programming Resistor (RES) Detect Circuit .. 20 5.5 V Input, 600 kHz Application Circuit ... 39 Valley Current-Limit Setting .. 20 300 kHz High Current Application Circuit .. 40 Hiccup Mode During Short Circuit ... 21 Outline Dimensions ... 41 Synchronous Rectifier .. 22 Ordering Guide .. 42
REVISION HISTORY 7/12—Rev. A to Rev. B
Changes to Table 2 and Table 3.. 5 Changed R Changes to Figure 3 and Table 4 .. 6 ON = 15 mΩ/100 kΩ Val ey Current Level Value from 7.5 to 3.87; Table 7 .. 21 Change to Figure 22 ... 10 Updated Outline Dimensions . ... .. ... ... ... ... ... ... ... ... ... ... .. .. 41 Changes to Figure 65 .. 18 Changes to Efficiency Considerations Section ... 26
6/10—Rev. 0 to Rev. A
Changes to Table 9 . ... .. ... ... ... ... ... ... ... ... ... .. .. ... ... ... ... 28 Added LFCSP Package ... Universal Added Figure 84; Renumbered Sequentially.. ... ... ... ... .. .. .. 28 Changes to Applications Section .. 1 Added Figure 96 . ... .. ... ... ... ... ... ... ... ... ... .. .. .. .. ... ... ... 41 Changes to Internal Regulator Characteristics Parameter, Changes to Ordering Guide .. ... ... ... .. .. .. .. ... ... ... ... ... ... 42 Table 1 .. 3
3/10—Revision 0: Initial Version
Rev. B | Page 2 of 44 Document Outline Features Applications General Description Typical Applications Circuit Revision History Specifications Absolute Maximum Ratings Thermal Resistance Boundary Condition ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics ADP1870/ADP1871 Block Diagram Theory of Operation Startup Soft Start Precision Enable Circuitry Undervoltage Lockout On-Board Low Dropout Regulator Thermal Shutdown Programming Resistor (RES) Detect Circuit Valley Current-Limit Setting Hiccup Mode During Short Circuit Synchronous Rectifier Power Saving Mode (PSM) Version (ADP1871) Timer Operation Pseudo-Fixed Frequency Applications Information Feedback Resistor Divider Inductor Selection Output Ripple Voltage (ΔVRR) Output Capacitor Selection Compensation Network Output Filter Impedance (ZFILT) Error Amplifier Output Impedance (ZCOMP) Error Amplifier Gain (GM) Current-Sense Loop Gain (GCS) Crossover Frequency Efficiency Considerations Channel Conduction Loss MOSFET Driver Loss Switching Loss Diode Conduction Loss Inductor Loss Input Capacitor Selection Thermal Considerations Design Example Input Capacitor Inductor Current Limit Programming Output Capacitor Feedback Resistor Network Setup Compensation Network Loss Calculations External Component Recommendations Layout Considerations IC Section (Left Side of Evaluation Board) Power Section Differential Sensing Typical Applications Circuits 15 A, 300 kHz High Current Application Circuit 5.5 V Input, 600 kHz Application Circuit 300 kHz High Current Application Circuit Outline Dimensions Ordering Guide
ADP1870/ADP1871 Data Sheet TABLE OF CONTENTS
Features .. 1 Power Saving Mode (PSM) Version (ADP1871).. 22 Applications ... 1 Timer Operation .. 22 General Description ... 1 Pseudo-Fixed Frequency ... 23 Typical Applications Circuit .. 1 Applications Information .. 24 Revision History ... 2 Feedback Resistor Divider .. 24 Specifications ... 3 Inductor Selection .. 24 Absolute Maximum Ratings .. 5 Output Ripple Voltage (ΔVRR) .. 24 Thermal Resistance .. 5 Output Capacitor Selection... 24 Boundary Condition .. 5 Compensation Network .. 25 ESD Caution .. 5 Efficiency Considerations ... 26 Pin Configuration and Function Descriptions ... 6 Input Capacitor Selection .. 27 Typical Performance Characteristics ... 7 Thermal Considerations .. 28 ADP1870/ADP1871 Block Diagram .. 18 Design Example .. 29 Theory of Operation .. 19 External Component Recommendations .. 31 Startup .. 19 Layout Considerations ... 33 Soft Start .. 19 IC Section (Left Side of Evaluation Board) ... 37 Precision Enable Circuitry .. 19 Power Section ... 37 Undervoltage Lockout ... 19 Differential Sensing .. 38 On-Board Low Dropout Regulator .. 19 Typical Applications Circuits .. 39 Thermal Shutdown ... 20 15 A, 300 kHz High Current Application Circuit .. 39 Programming Resistor (RES) Detect Circuit .. 20 5.5 V Input, 600 kHz Application Circuit ... 39 Valley Current-Limit Setting .. 20 300 kHz High Current Application Circuit .. 40 Hiccup Mode During Short Circuit ... 21 Outline Dimensions ... 41 Synchronous Rectifier .. 22 Ordering Guide .. 42
REVISION HISTORY 7/12—Rev. A to Rev. B
Changes to Table 2 and Table 3.. 5 Changed R Changes to Figure 3 and Table 4 .. 6 ON = 15 mΩ/100 kΩ Val ey Current Level Value from 7.5 to 3.87; Table 7 .. 21 Change to Figure 22 ... 10 Updated Outline Dimensions . ... .. ... ... ... ... ... ... ... ... ... ... .. .. 41 Changes to Figure 65 .. 18 Changes to Efficiency Considerations Section ... 26
6/10—Rev. 0 to Rev. A
Changes to Table 9 . ... .. ... ... ... ... ... ... ... ... ... .. .. ... ... ... ... 28 Added LFCSP Package ... Universal Added Figure 84; Renumbered Sequentially.. ... ... ... ... .. .. .. 28 Changes to Applications Section .. 1 Added Figure 96 . ... .. ... ... ... ... ... ... ... ... ... .. .. .. .. ... ... ... 41 Changes to Internal Regulator Characteristics Parameter, Changes to Ordering Guide .. ... ... ... .. .. .. .. ... ... ... ... ... ... 42 Table 1 .. 3
3/10—Revision 0: Initial Version
Rev. B | Page 2 of 44 Document Outline Features Applications General Description Typical Applications Circuit Revision History Specifications Absolute Maximum Ratings Thermal Resistance Boundary Condition ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics ADP1870/ADP1871 Block Diagram Theory of Operation Startup Soft Start Precision Enable Circuitry Undervoltage Lockout On-Board Low Dropout Regulator Thermal Shutdown Programming Resistor (RES) Detect Circuit Valley Current-Limit Setting Hiccup Mode During Short Circuit Synchronous Rectifier Power Saving Mode (PSM) Version (ADP1871) Timer Operation Pseudo-Fixed Frequency Applications Information Feedback Resistor Divider Inductor Selection Output Ripple Voltage (ΔVRR) Output Capacitor Selection Compensation Network Output Filter Impedance (ZFILT) Error Amplifier Output Impedance (ZCOMP) Error Amplifier Gain (GM) Current-Sense Loop Gain (GCS) Crossover Frequency Efficiency Considerations Channel Conduction Loss MOSFET Driver Loss Switching Loss Diode Conduction Loss Inductor Loss Input Capacitor Selection Thermal Considerations Design Example Input Capacitor Inductor Current Limit Programming Output Capacitor Feedback Resistor Network Setup Compensation Network Loss Calculations External Component Recommendations Layout Considerations IC Section (Left Side of Evaluation Board) Power Section Differential Sensing Typical Applications Circuits 15 A, 300 kHz High Current Application Circuit 5.5 V Input, 600 kHz Application Circuit 300 kHz High Current Application Circuit Outline Dimensions Ordering Guide
