Datasheet ADP1829 (Analog Devices) - 10

ADP1829 Data Sheet 4.960 0.6010 0.6005 4.956 ) V ( E 0.6000 4.952 AG T L (V) O 0.5995 EG VR 4.948 DBACK V 0.5990 E E F 4.944 0.5985 4.940 0.5980 0 20 40 60 80 100
010
–40 –15 10 35 60 85
013
LOAD CURRENT (mA) TEMPERATURE (°C)
06784- 06784- Figure 10. VREG vs. Load Current, VIN = 12 V Figure 13. Feedback Voltage vs. Temperature, VIN = 12 V
330 5 320 4 310 ) (V) T Hz ( PU 3 300 T U NCY O UE 290 EG Q 2 VR RE F 280 1 270 0 260 0 50 100 150 200 250
011
–40 –15 10 35 60 85
014
LOAD CURRENT (mA)
06784-
TEMPERATURE (°C)
06784- Figure 11. VREG Current-Limit Foldback Figure 14. Switching Frequency vs. Temperature, VIN = 12 V
5 T 4 mA) VREG, AC-COUPLED, 1V/DIV ( NT 3 CURRE Y 2 SW1 PIN, V L OUT = 1.8V, 10V/DIV P UP S 1 SW2 PIN, VOUT = 1.2V, 10V/DIV
012
200ns/DIV 0
06784-
2 5 8 11 14 17 20
015
SUPPLY VOLTAGE (V)
06784- Figure 12. VREG Output During Normal Operation Figure 15. Supply Current vs. Input Voltage Rev. D | Page 10 of 28 Document Outline FEATURES APPLICATIONS TYPICAL APPLICATION CIRCUIT GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION FUNCTIONAL BLOCK DIAGRAM PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION INPUT POWER START-UP LOGIC INTERNAL LINEAR REGULATOR OSCILLATOR AND SYNCHRONIZATION ERROR AMPLIFIER SOFT START POWER OK INDICATOR TRACKING MOSFET DRIVERS CURRENT LIMIT APPLICATIONS INFORMATION SELECTING THE INPUT CAPACITOR Selecting the Output LC Filter SELECTING THE MOSFETS SETTING THE CURRENT LIMIT FEEDBACK VOLTAGE DIVIDER COMPENSATING THE VOLTAGE MODE BUCK REGULATOR Type II Compensator Type III Compensator SOFT START VOLTAGE TRACKING COINCIDENT TRACKING RATIOMETRIC TRACKING Setting the Channel 2 Undervoltage Threshold for Ratiometric Tracking THERMAL CONSIDERATIONS PCB LAYOUT GUIDELINES LFCSP PACKAGE CONSIDERATIONS APPLICATION CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE