S-8340/8341 Series STEP-UP, 600 kHz, PWM CONTROL OR PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER www.sii-ic.com SII Semiconductor Corporation, 1999-2010 Rev.4.0 01 The S-8340/8341 Series is a CMOS step-up switching regulator controller which mainly consists of a reference voltage source, oscillation circuit, error amplifier, phase compensation circuit, PWM control circuit (S-8340 Series), and PWM/PFM switching control circuit (S-8341 Series). Since the oscillation frequency is a high 300 kHz or 600 kHz, with the addition of a small external part, the S-8340/8341 Series functions as a highly efficient step-up switching regulator with a high output current. The speed of the output stage is enhanced so that the N-channel power MOS with a low on-resistance can be switched quickly. The S-8340 Series realizes low ripple, high efficiency, and excellent transient characteristics thanks to a PMW control circuit capable of varying the duty ratio linearly from 0 to 82%, optimized error amplifier, and phase compensation circuit. The S-8341 Series contains a PWM/PFM switching control circuit so that it operates using PWM control with a duty ratio of 27% or higher and using PFM control with a duty ratio of lower than 27% to ensure high efficiency in all load ranges. These S-8340/8341 Series serve as ideal main power supply units for portable devices when coupled with the 8-Pin TSSOP package and high oscillation frequencies. Features Oscillation frequency : 600 kHz (A and B types), 300 kHz (C and D types). Output voltage : Selectable in 0.1 V steps between 2.5 to 6.0 V (output voltage fixed output type) Output voltage accuracy : 2.0% Output voltage external setting (FB) type available. FB terminal voltage (VFB) 1.0 V External parts : Coil, diode, capacitors (3), transistor, and resistor only Duty ratio : 0 to 82% (typ.) PWM control (S-8340 Series) 27 to 82% (typ.) PWM/PFM switching control (S-8341 Series A and B types) 21 to 82% (typ.) PWM/PFM switching control (S-8341 Series C and D types) Low-voltage operation: Oscillation guaranteed to start when VDD = 0.9 V Built-in current limit circuit: Can be set with an external resistor (RSENSE) Soft-start function set by an external capacitor (CSS) Shutdown function *1 Lead-free, Sn 100%, halogen-free *1. Refer to Product Name Structure for details. Applications Power supplies for portable equipments such as PDAs, electronic notebooks, and cellular phones Power supplies for audio equipments such as portable CD players, portable MD players, and headphone stereos Main or local power supplies for notebook PCs and peripherals Constant voltage power supplies for cameras, VCRs, and communication devices Package 8-Pin TSSOP 1 STEP-UP, 600 kHz, PWM CONTROL OR PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8340/8341 Series Rev.4.0 01 Block Diagrams (1) S-8340/8341 Series A and C Types (Output Voltage Fixed Output Type) L V OUT SD VDD Phase Triangular wave compensation oscillation circuit circuit IC internal power PWM comparator VOUT supply EXT V IN C Nch Power C R MOS FET 1 + R S Error amplifier C L SENSE C S PWM, PWM/PFM R2 switching control circuit VSS 120 mV V =1.0 V REF R SENSE Voltage/current Shutdown Soft-start reference circuit circuit CSS CVREF C C ON/OFF SS VREF Figure 1 (2) S-8340/8341 Series B and D Types (Output Voltage External Setting Type) L V SD OUT VDD Phase Triangular wave compensation oscillation circuit circuit IC internal power PWM comparator supply EXT V IN Nch Power MOS FET C FB + R S R FB1 Error amplifier FB C L SENSE C S PWM, PWM/PFM R FB2 switching control circuit V =1.0 V 120 mV REF R SENSE VSS Shutdown Soft-start Voltage/current reference circuit circuit CSS CVREF C C ON/OFF SS VREF Figure 2 2