Datasheet ADP2300, ADP2301 (Analog Devices) - 22
| Manufacturer | Analog Devices |
| Description | 1.2 A, 20 V, 1.4 MHz non-synchronous step-down switching regulator |
| Pages / Page | 28 / 22 — ADP2300/ADP2301. Data Sheet. RESISTIVE VOLTAGE DIVIDER SELECTION. BST. IN … |
| Revision | C |
| File Format / Size | PDF / 616 Kb |
| Document Language | English |
ADP2300/ADP2301. Data Sheet. RESISTIVE VOLTAGE DIVIDER SELECTION. BST. IN = 12V. VIN. 0.1µF. 10µF. 6.3V. 4.7µH. 25V. OUT = 3.3V. ADP2301. 2.0A
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ADP2300/ADP2301 Data Sheet RESISTIVE VOLTAGE DIVIDER SELECTION
The resistive voltage divider for the programmable VIN start-up To select the appropriate resistive voltage divider, first calculate the voltage is output feedback resistive voltage divider, and then calculate the 1.2 V resistive voltage divider for the programmable V V = + STARTUP 1.2 μA × R + EN1 1.2 V IN start-up voltage. REN2 The output feedback resistive voltage divider is If VSTARTUP = 7.8 V, choose REN2 = 10.2 kΩ, and then calculate R V = 0.800 V× 1 FB REN1, which in this case is 56 kΩ. OUT 1+ RFB2 For the 3.3 V output voltage, choose RFB1 = 31.6 kΩ and RFB2 = 10.2 kΩ as the feedback resistive voltage divider, according to the recommended values in Table 11.
V BST IN = 12V VIN C3 C1 0.1µF 10µF 6.3V L1 4.7µH V 25V OUT = 3.3V ADP2301 2.0A 1.2A SW (1.4MHz) C2 R3 D1 22µF 56kΩ B230A 6.3V 1% R1 31.6kΩ 1% EN FB R4 10.2kΩ GND R2 10.2k 1% Ω
045
1%
08342- Figure 48. Schematic for the Design Example
Table 11. Recommended External Components for Typical Applications at 1.2 A Output Load Part Number V (V) V (V) I (A) L (µH) C (µF) R (kΩ), ±1% R (kΩ), ±1% IN OUT OUT OUT FB1 FB2
ADP2300 (700 kHz) 18 3.3 1.2 10 22 31.6 10.2 18 5.0 1.2 15 22 52.3 10 12 1.2 1.2 6.8 2 × 22 4.99 10 12 1.8 1.2 6.8 2 × 22 12.7 10.2 12 2.5 1.2 10 22 21.5 10.2 12 3.3 1.2 10 22 31.6 10.2 12 5.0 1.2 10 22 52.3 10 9 3.3 1.2 10 22 31.6 10.2 9 5.0 1.2 10 22 52.3 10 5 1.8 1.2 4.7 2 × 22 12.7 10.2 5 2.5 1.2 4.7 22 21.5 10.2 ADP2301 (1.4 MHz) 18 3.3 1.2 4.7 22 31.6 10.2 18 5.0 1.2 6.8 10 52.3 10 12 2.5 1.2 4.7 22 21.5 10.2 12 3.3 1.2 4.7 22 31.6 10.2 12 5.0 1.2 4.7 10 52.3 10 9 3.3 1.2 4.7 22 31.6 10.2 9 5.0 1.2 4.7 10 52.3 10 5 1.8 1.2 2.2 2 × 22 12.7 10.2 5 2.5 1.2 2.2 22 21.5 10.2 Rev. C | Page 22 of 28 Document Outline Features Applications Typical Applications Circuit General Description Revision History Specifications Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Functional Block Diagram Theory of Operation Basic Operation PWM Mode Power Saving Mode Bootstrap Circuitry Precision Enable Integrated Soft Start Current Limit Short-Circuit Protection Undervoltage Lockout (UVLO) Thermal Shutdown Control Loop Applications Information ADIsimPower Design Tool Programming the Output Voltage Voltage Conversion Limitations Low Input Voltage Considerations Programming the Precision Enable Inductor Catch Diode Input Capacitor Output Capacitor Thermal Considerations Design Example Switching Frequency Selection Catch Diode Selection Inductor Selection Output Capacitor Selection Resistive Voltage Divider Selection Circuit Board Layout Recommendations Typical Application Circuits Outline Dimensions Ordering Guide
ADP2300/ADP2301 Data Sheet RESISTIVE VOLTAGE DIVIDER SELECTION
The resistive voltage divider for the programmable VIN start-up To select the appropriate resistive voltage divider, first calculate the voltage is output feedback resistive voltage divider, and then calculate the 1.2 V resistive voltage divider for the programmable V V = + STARTUP 1.2 μA × R + EN1 1.2 V IN start-up voltage. REN2 The output feedback resistive voltage divider is If VSTARTUP = 7.8 V, choose REN2 = 10.2 kΩ, and then calculate R V = 0.800 V× 1 FB REN1, which in this case is 56 kΩ. OUT 1+ RFB2 For the 3.3 V output voltage, choose RFB1 = 31.6 kΩ and RFB2 = 10.2 kΩ as the feedback resistive voltage divider, according to the recommended values in Table 11.
V BST IN = 12V VIN C3 C1 0.1µF 10µF 6.3V L1 4.7µH V 25V OUT = 3.3V ADP2301 2.0A 1.2A SW (1.4MHz) C2 R3 D1 22µF 56kΩ B230A 6.3V 1% R1 31.6kΩ 1% EN FB R4 10.2kΩ GND R2 10.2k 1% Ω
045
1%
08342- Figure 48. Schematic for the Design Example
Table 11. Recommended External Components for Typical Applications at 1.2 A Output Load Part Number V (V) V (V) I (A) L (µH) C (µF) R (kΩ), ±1% R (kΩ), ±1% IN OUT OUT OUT FB1 FB2
ADP2300 (700 kHz) 18 3.3 1.2 10 22 31.6 10.2 18 5.0 1.2 15 22 52.3 10 12 1.2 1.2 6.8 2 × 22 4.99 10 12 1.8 1.2 6.8 2 × 22 12.7 10.2 12 2.5 1.2 10 22 21.5 10.2 12 3.3 1.2 10 22 31.6 10.2 12 5.0 1.2 10 22 52.3 10 9 3.3 1.2 10 22 31.6 10.2 9 5.0 1.2 10 22 52.3 10 5 1.8 1.2 4.7 2 × 22 12.7 10.2 5 2.5 1.2 4.7 22 21.5 10.2 ADP2301 (1.4 MHz) 18 3.3 1.2 4.7 22 31.6 10.2 18 5.0 1.2 6.8 10 52.3 10 12 2.5 1.2 4.7 22 21.5 10.2 12 3.3 1.2 4.7 22 31.6 10.2 12 5.0 1.2 4.7 10 52.3 10 9 3.3 1.2 4.7 22 31.6 10.2 9 5.0 1.2 4.7 10 52.3 10 5 1.8 1.2 2.2 2 × 22 12.7 10.2 5 2.5 1.2 2.2 22 21.5 10.2 Rev. C | Page 22 of 28 Document Outline Features Applications Typical Applications Circuit General Description Revision History Specifications Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Functional Block Diagram Theory of Operation Basic Operation PWM Mode Power Saving Mode Bootstrap Circuitry Precision Enable Integrated Soft Start Current Limit Short-Circuit Protection Undervoltage Lockout (UVLO) Thermal Shutdown Control Loop Applications Information ADIsimPower Design Tool Programming the Output Voltage Voltage Conversion Limitations Low Input Voltage Considerations Programming the Precision Enable Inductor Catch Diode Input Capacitor Output Capacitor Thermal Considerations Design Example Switching Frequency Selection Catch Diode Selection Inductor Selection Output Capacitor Selection Resistive Voltage Divider Selection Circuit Board Layout Recommendations Typical Application Circuits Outline Dimensions Ordering Guide