Datasheet
ADP1874/ADP1875 Data Sheet
Rev. A | Page 2 of 44
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
General Description ......................................................................... 1
Typical Applications Circuit ............................................................ 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 6
Thermal Resistance ...................................................................... 6
Boundary Condition .................................................................... 6
ESD Caution .................................................................................. 6
Pin Configuration and Function Descriptions ............................. 7
Typical Performance Characteristics ............................................. 8
ADP1874/ADP1875 Block Digram ............................................... 18
Theory of Operation ...................................................................... 19
Startup .......................................................................................... 19
Soft Start ...................................................................................... 19
Precision Enable Circuitry ........................................................ 19
Undervoltage Lockout ............................................................... 19
On-Board Low Dropout Regulator .......................................... 20
Thermal Shutdown ..................................................................... 20
Programming Resistor (RES) Detect Circuit .......................... 20
Valley Current-Limit Setting .................................................... 20
Hiccup Mode During Short Circuit ......................................... 22
Synchronous Rectifier ................................................................ 22
ADP1875 Power Saving Mode (PSM) ...................................... 22
Timer Operation ........................................................................ 23
Pseudo-Fixed Frequency ........................................................... 24
Power Good Monitoring ........................................................... 24
Voltage Tracking ......................................................................... 25
Applications Information .............................................................. 27
Feedback Resistor Divider ........................................................ 27
Inductor Selection ...................................................................... 27
Output Ripple Voltage (ΔV
RR
) .................................................. 27
Output Capacitor Selection....................................................... 27
Compensation Network ............................................................ 28
Efficiency Consideration ........................................................... 29
Input Capacitor Selection .......................................................... 30
Thermal Considerations ............................................................ 31
Design Example .......................................................................... 32
External Component Recommendations .................................... 34
Layout Considerations ................................................................... 36
IC Section (Left Side of Evaluation Board) ............................. 38
Power Section ............................................................................. 38
Differential Sensing .................................................................... 39
Typical Application Circuits ......................................................... 40
12 A, 300 kHz High Current Application Circuit .................. 40
5.5 V Input, 600 kHz Application Circuit ............................... 40
300 kHz High Current Application Circuit ............................ 41
Outline Dimensions ....................................................................... 42
Ordering Guide .......................................................................... 42
REVISION HISTORY
7/12—Rev. 0 to Rev. A
Changes to Table 7 .......................................................................... 21
3/11—Revision 0: Initial Version