AS1337 Datasheet | austriamicrosystems AG

Description The AS1337 is a synchronous, fixed frequency, highefficiency DC-DC boost converter capable of supplying 3.3V @ 200m A from two AA Cells. pact size and minimum external parts requirements make these devices perfect for modern portable devices. The AS1337 offers automatic powersave mode to increase efficiency at light loads. For input voltages higher than VOUT the AS1337 will switch in a step down mode, so that a Buck Boost function is realized. The AS1337A offers a shutdown mode where the battery is connected directly to the output enabling the supply of real-time-clocks or memories. The AS1337 offers a POK (open-drain) feature which detects output power fail of 10%. The AS1337 is available in a TDFN (3x3mm) 8-pin package. 2 Key Features ! ! ! ! ! ! ! ! ! ! ! ! Input Voltage Range: 0.65V to 4.5V Low Start-Up Voltage: 0.85V Output Voltage Range: 2.5V to 5.0V Delivers 200m A @ 3.3V (from two AA Cell) up to 97% Efficiency High-Speed Fixed-Frequency: 1.2MHz Single-Cell Operation Internal PMOS Synchronous Rectifier Automatic Powersave Operation Anti-Ringing Control Minimizes EMI Logic Controlled Shutdown (< 1µA) TDFN (3x3mm) 8-pin Package 3 Applications The AS1337 is ideal for low-power applications where ultra-small size is critical as in medical diagnostic equipment, hand-held instruments, pagers, digital cameras, remote wireless transmitters, MP3 players, LCD bias supplies, cordless phones, GPS receivers, and PC cards. Figure 1. AS1337 - Typical Application Diagram - Dual Cell to 3.3V Synchronous Boost Converter 3.6V Buck Mode VOUT=3.3V 2x AA Cell Range VIN Curve Boost Mode L1 4.7µH VIN = 2x AA 1.6V to 3.6V CIN 10µF On Off VOUT = 3.3V LX VIN VOUT FB COUT 22µF EN GND POK PGND 1.6V .austriamicrosystems. Revision 1.03 - 14 - P i n A s s i g n m e n t s .. 4 Pin Assignments Figure 2. Pin Assignments (Top View) VOUT 1 LX 2 8 FB 7 VIN PGND 3 GND 4 6 POK 5 EN 9 GND Pin Descriptions Table 1. Pin Descriptions Pin...