S-8580AA/8580AB/8581AA/8581AB Series 36 V INPUT, 600 mA SYNCHRONOUS www.ablic.com STEP-DOWN SWITCHING REGULATOR ABLIC Inc., 2019-2021 Rev.2.1 00 The S-8580/8581 Series is a step-down switching regulator developed using high withstand voltage CMOS process technologies. This IC has high maximum operation voltage of 36 V and maintains high-accuracy FB pin voltage at 1.5%. As suitable packages for high-density mounting, such as small-sized HSNT-6(2025), are adopted, this IC contributes to miniaturization of electronic equipment. PWM control (S-8580 Series) or PWM / PFM switching control (S-8581 Series) can be selected as an option. Since the S-8581 Series, which features PWM / PFM switching control, operates with PWM control under heavy load and automatically switches to PFM control under light load, it achieves high-efficiency operation in accordance with the device s status. Furthermore, our distinctive PWM / PFM switching control technology suppresses the ripple voltage to be generated in VOUT while PFM control is in operation. Since the S-8580/8581 Series has the built-in synchronous circuit, it achieves high efficiency easier compared with conventional step-down switching regulators. In addition, it has the built-in overcurrent protection circuit which protects the IC and coils from excessive load current as well as a thermal shutdown circuit which prevents damage from heat generation. Features Applications Input voltage: 4.0 V to 36.0 V Constant-voltage power supply Output voltage (externally set): 2.5 V to 30.0 V (S-8580 Series) for industrial equipment 2.5 V to 12.0 V (S-8581 Series) Output current: 600 mA Constant-voltage power supply FB pin voltage accuracy: 1.5% for home electric appliance Efficiency: 91% Oscillation frequency: 2.2 MHz typ. Packages Overcurrent protection function: 1.2 A typ. (pulse-by-pulse method) Thermal shutdown function: 170C typ. (detection temperature) HTMSOP-8 Short-circuit protection function: Hiccup control, Latch control (4.0 mm 2.9 mm t0.8 mm max.) 100% duty cycle operation: HSNT-8(2030) Soft-start function: 5.8 ms typ. (3.0 mm 2.0 mm t0.5 mm max.) Under voltage lockout function (UVLO): 3.35 V typ. (detection voltage) HSNT-6(2025) Input and output capacitors: Ceramic capacitor compatible (2.46 mm 1.96 mm t0.5 mm max.) Operation temperature range: Ta = 40C to +85C Lead-free (Sn 100%), halogen-free Typical Application Circuit Efficiency V = 24.0 V, V = 5.0 V IN OUT VIN VIN L VOUT 100 4.7 H 5.0 V S-8581 Series VEN EN SW 80 60 CFB RFB1 CIN 4.7 F 33 pF 84 k 40 FB VREG CREG COUT VSS 20 1 F 10 F S-8580 Series RFB2 0 16 k 0.1 1 10 100 1000 IOUT mA 1 % 36 V INPUT, 600 mA SYNCHRONOUS STEP-DOWN SWITCHING REGULATOR S-8580AA/8580AB/8581AA/8581AB Series Rev.2.1 00 Block Diagrams 1. S-8580 Series (PWM control) VIN *1 *1 EN VREG Enable VIN CIN Regulator circuit *1 *1 UVLO circuit CREG *1 Soft-start VREG circuit SW VOUT *1 + FB Error L amplifier CFB RFB1 PWM *1 COUT *1 control + circuit RFB2 Oscillation circuit VREF Short-circuit protection circuit VSS *1. Parasitic diode Figure 1 2. S-8581 Series (PWM / PFM switching control) VIN *1 *1 EN VREG Enable VIN CIN Regulator circuit *1 *1 UVLO circuit CREG *1 Soft-start VREG circuit SW VOUT *1 FB + Error L CFB RFB1 amplifier COUT *1 *1 switching + RFB2 Oscillation circuit VREF Reverse current detection Short-circuit circuit protection circuit VSS *1. Parasitic diode Figure 2 2