STEVAL-ISA083V1 4 A peak 800 kHz fixed-frequency PWM synchronous step-down demonstration board with enable on/off based on the ST1S40IPUR Data brief Features ■ Input voltage V : 4 V to 18 V in ■ Output voltage V : 3.3 V out ■ Maximum output current: 4 A ■ Switching frequency: 800 kHz ■ Short-circuit protected ■ RoHS compliant Description The STEVAL-ISA083V1, based on the ST1S40IPUR, is an internally compensated 800 kHz fixed-frequency PWM synchronous step- STEVAL-ISA083V1 down converter demonstration board. The ST1S40 operates from 4.0 V to 18.0 V input, while it regulates an output voltage as low as 0.8 V and up to V (100% duty cycle). IN The ST1S40 integrates a 95 mΩ high-side switch and a 69 mΩ synchronous rectifier allowing very high efficiency with very low output voltage. The peak current mode control with internal compensation delivers a very compact solution with a minimum component count. The ST1S40 is protected through cycle-by-cycle current limiting in case of overload and is also protected by a current foldback function with frequency reduction in case of short-circuit. The device is available with an enable on/off function. September 2011 Doc ID 022278 Rev 1 1/4 For further information contact your local STMicroelectronics sales office. www.st.com 4

Schematic STEVAL-ISA083V1 1 Schematic Figure 1. Circuit schematic (cid:44) (cid:19)(cid:14)(cid:19)(cid:151)(cid:40) (cid:54)(cid:41)(cid:46)(cid:8)(cid:17)(cid:18)(cid:54)(cid:9) (cid:54)(cid:47)(cid:53)(cid:52)(cid:0)(cid:8)(cid:19)(cid:14)(cid:19)(cid:54)(cid:9) (cid:54)(cid:41)(cid:46)(cid:51)(cid:55) (cid:51)(cid:55) (cid:54)(cid:41)(cid:46)(cid:33) (cid:35)(cid:73)(cid:78)(cid:63)(cid:65) (cid:50)(cid:17) (cid:37)(cid:46)(cid:15)(cid:48)(cid:39) (cid:51)(cid:52)(cid:17)(cid:51)(cid:20)(cid:16) (cid:16)(cid:14)(cid:17)(cid:110)(cid:17)(cid:0)(cid:151)(cid:38) (cid:38)(cid:34) (cid:35)(cid:79)(cid:85)(cid:84) (cid:35)(cid:73)(cid:78)(cid:63)(cid:83)(cid:87) (cid:48)(cid:39)(cid:46)(cid:36)(cid:15)(cid:33)(cid:39)(cid:46)(cid:36) (cid:50)(cid:18) (cid:18)(cid:18)(cid:151)(cid:38) (cid:17)(cid:16)(cid:151)(cid:38) 2/4 Doc ID 022278 Rev 1

STEVAL-ISA083V1 Revision history 2 Revision history Table 1. Document revision history Date Revision Changes 27-Sep-2011 1 Initial release. Doc ID 022278 Rev 1 3/4

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