Panasonic AN8049SH free download

File name AN8049SH.pdf

Voltage Regulators AN8049SH 1.8-volt 3-channel step-up, step-down, and polarity inverting DC-DC converter control IC Unit : mm s Overview The AN8049SH is a three-channel PWM DC-DC converter control IC that features low-voltage operation. This IC can form a power supply that provides two stepup outputs and one step-down or polarity inverted output with a minimal number of external components. The AN8049SH features the ability to operate from a supply voltage as low as 1.8 V, and thus can be operated from two dry-batteries. 6.5±0.3 24 13 5.5±0.3 7.5±0.3 0.15 ­ 0.05 +0.10 0° to 10° (0.50) s Features (0.50) 0.50 Seating plane 0.2±0.1 0.65±0.10 0.1±0.1 0.65±0.10 1.5±0.2 1 12 Seating plane · Wide operating supply voltage range: 1.8 V to 14 V · High-precision reference voltage circuit SSOP024-P-0300A -- VREF pin voltage: ±1% -- Error amplifier: ±1.5% · Surface mounting package for miniaturized and thinner power supplies Package: SSOP-24D 0.5-mm lead pitch 7.8 mm Ч 6.8 mm Ч t 1.9 mm · Supports control over a wide output frequency range: 20 kHz to 1 MHz · On/off (sequence control) pins provided for each channel for easy sequence control setup · The negative supply error amplifier supports 0-volt input. Common-mode input voltage range: - 0.1 V to VCC -1.4 V This allows the number of external components to be reduced by two resistors. · Fixed duty factor: 86% However, the duty can be adjusted to anywhere from 0% to 100% with an external resistor. · Timer latch short-circuit protection circuit (charge current: 1.1 µA typical) · Low input voltage malfunction prevention circuit (U.V.L.O.) (operation start voltage: 1.67 V typical) · Standby function (active-high control input, standby mode current: 1 µA maximum) · Alternate package versions also available. Part No.: AN8049FHN Package: QFN-24 0.5-mm lead pitch 5.4 mm Ч 4.4 mm Ч t 0.8 mm s Applications · Electronic equipment that requires a power supply system 1 AN8049SH s Block Diagram CTL1 VREF OSC IN-1 DT1 VCC FB1 Voltage Regulators 23 24 7 4 17 16 1.1 µA 45 k Reference voltage supply VREF 9 Sawtooth wave generator 1.26 V (Allowance: ±1%) Error amplifier 1 1.26 V S.C.P. FB3 1 20 Error amplifier 2 20 k 1.26 V VCC 1.1 µA S.C.P. comp. 0.9 V U.V.L.O. R Q S Latch 1.26 V 55 k 0.7 V On/off VCC 0.3 V control 11 12 8 Off RB1 OUT1 PWM1 DT3 CTL3 2 5 Error amplifier 3 56 k 44 k 18 IN+3 19 IN-3 PWM3 15 27 k OUT3 VCC PWM2 1.26 V 13 VREF 45 k 10 RB2 OUT2 14 VREF 1.1 µA 20 k 20 k 1.26 V 1.1 µA 1.26 V 27 k 21 22 6 CTL2 IN-2 s Pin Descriptions Pin No. 1 Symbol S.C.P. Description Connection for the capacitor that provides the shortcircuit protection circuit time constant Channel 3 soft start setting Channel 2 soft start setting Channel 1 soft start setting Channel 3 on/off control Channel 2 on/off control Channel 1 on/off control On/off control Reference voltage output Connection for the OUT2 block output source current setting resistor Connection for the OUT1 block outpu