ST755CD

ST755C Adjustable inverting negative output current mode PWM regulators Features ■ 2.7V to 11V input to adjustable negative output conversion ■ 1W guaranteed output power (VI > 4.5V, TA ≤ 70°C) ■ 68% typ. efficiency at 6V ■ Very low quiescent current: 1.2mA in on mode, 10µA in shut down mode ■ Soft start ■ Very low noise output ■ 160KHz fixed frequency oscillator ■ Mixed bipolar-CMOS technology SO-8 ) s t( and TA = 0°C to 70°C) and 275mA (typical value at TA = 25°C, VO = -5V). c u d o r A logic controlled shut down pin that interfaces directly with microprocessor reduces supply current to only 10mA. Input to Output differential voltage is limited to VI+|VO| 4.5V, VO = -5V P e et O ) s ( t c u d o r eP t e ol s b O Table 1. July 2007 Device summary Part number Package Packaging ST755C ST755CD-TR SO-8 (tape & reel) Rev. 5 1/16 www.st.com 16 ST755C Contents 1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6 Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 ) s t( c u d o r l o bs O ) s ( t c u d o r eP t e ol s b O 2/16 P e et ST755C Diagram 1 Diagram Figure 1. Schematic diagram ) s t( c u d o r l o bs P e et O ) s ( t c u d o r eP t e ol s b O 3/16 Pin configuration ST755C 2 Pin configuration Figure 2. Pin connections (top view) Table 2. Pin description Pin N° Symbol Name and function 1 SHDN SHUT-DOWN control (VCC = ON, GND = Shutdown) 2 VREF Reference output voltage: (1.25V) 3 SS Soft start 4 CC Compensation input 5 VO Negative output voltage 6 GND 7 LX 8 VCC Switch output s ( t c u d Supply voltage input s b O 4/16 l o bs O ) Ground o r eP t e ol c u d o r ) s t( P e et ST755C Maximum ratings 3 Maximum ratings Table 3. Absolute maximum ratings Symbol VCC VSHDN Parameter DC input voltage to GND (1) Shutdown voltage, SS Voltage, CC Voltage VLX Switch voltage (LX to VCC) VFB Feedback voltage (VO to GND) ILX Peak switch current PTOT Value Unit -0.3 to 12 V -0.3 to (VCC + 0.3) V -12.5 to + 0.3 V -11 to + 0.9 V 2 A 470 mW Continuous power dissipation at TA = 70°C (SO-8) Top Operating junction temperature range (C series) -40 to 185 °C Tstg Storage temperature range -55 to +150 °C ) s t( 1. The input to output differential voltage is limited to VCC+|VO|