ADP1147-3.3 Datasheet | Analog Devices

FEATURES Greater Than 95% Efficiency Current Mode Switching Architecture Provides Superior Load and Line Transient Response Wide Input Voltage Range 3.5 V- to 16 V User Defined Current Limit Short Circuit Protection Shutdown Pin Low Dropout Voltage Low Standby Current 160 ␮A typ Low Cost Available in 8-Lead PDIP or 8-Lead SOIC APPLICATIONS Portable puters Modems Cellular Telephones Portable Equipment GPS Systems Handheld Instruments GENERAL DESCRIPTION The ADP1147 is part of a family of High Efficiency Step-Down Switching Regulators. These regulators offer superior load and line transient response, a user defined current limit and an automatic power savings mode. The automatic power savings mode is used to maintain efficiency at lower output currents. The ADP1147 incorporates a constant off-time, current mode switching architecture to drive an external P-channel MOSFET at frequencies up to 250 k Hz. Constant off-time switching generates a constant ripple current in the external inductor. This results in a wider input voltage operating range of 3.5 V- to 16 V, and a less plex circuit design. - 3.5 volt operation is for the ADP1147-3.3. VIN (5.2V TO 12V) + 1␮F + CIN 100␮F P-CHANNEL IRF7204 L- 50␮H D1 30BQ040 RSENSE- - 0.05⍀ VOUT 5V/2A + COUT 390␮F 0V = NORMAL 1.5V = SHUTDOWN VIN P-DRIVE CC RC 3300p F 1k⍀ ADP1147 SHUTDOWN ITH SENSE(+) CT SENSE(- ) 470p F 1000p F - COILTRONICS CTX 50- 2MP - - KRL SL-1-C1-0R050J SHUTDOWN Figure 1. High Efficiency Step-Down Converter (Typical Application) FUNCTIONAL BLOCK DIAGRAM VIN P-DRIVE GROUND SENSE(+) SENSE(- ) ADP1147 SLEEP S VTH2 VTH1 QR...