For assistance or to order, call (800) 531-5782 78ST212 Series 12V 2 AMP POSITIVE STEP-DOWN INTEGRATED SWITCHING REGULATOR Standard Application • High Efficiency > 87% • Wide Input Range • Aluminum Heatsink for Applications with Airflow • Self-Contained Inductor • Short Circuit Protection • Over-Temperature Protection The 78ST212 is a series of wide input voltage, 3-terminal Integrated Switching Regulators (ISRs). With a surge capability of 3A and an output voltage that is laser trimmed, it is ideal for inductive load applications such as disk drive motors. Pin-Out Information Ordering Information Pin Function 1 Vin 2 GND Vout 3 Vin 1 78ST212 C1 2 C2 78ST2 XX Y C Output Voltage Package Suffix 12 = 12.0 Volts V = Vertical Mount H = Horizontal Mount Vout 3 Revised 6/30/98 + GND GND (For dimensions and PC board layout see Package Style 600.) C1 = Optional 1µF ceramic C2 = Required 100µF electrolytic Specifications 78ST212 SERIES Characteristics (Ta = 25°C unless noted) Symbols Conditions Min Typ Max Units Output Current Io Over Vin range With forced air cooling 0.1* — 2.0 A Input Voltage Range Output Voltage Tolerance Vin ∆Vo 0.1 ≤ Io ≤ 2.0A Over Vin range, Io= 2.0A Ta= 0°C to +55°C 14.5 — 28 V — ±1.0 ±2.0 %Vo Line Regulation Regline Over Vin range — ±0.4 ±0.8 %Vo Load Regulation Regload 0.1 ≤ Io ≤ 2.0A — ±0.2 ±0.4 %Vo Vo Ripple/Noise Vn Vin=17V, Io=2.0A, Vo=12V — 1.0 — %Vo Transient Response (with 100µF output cap) ttr 50% load change Vo over/undershoot — — 100 3.0 — — µSec %Vo Efficiency η Vin=17V, Io=2.0A — 87 — % Switching Frequency ƒo Over Vin and Io ranges 0.95 1.0 1.05 MHz Absolute Maximum Operating Temperature Range Ta — -40 — +65 °C Recommended Operating Temperature Range Ta Free Air Convection, (40-60LFM) at Vin= 24V, Io=2A -40 — +55** °C Thermal Resistance θja Free Air Convection, (40-60LFM) — 35 — °C/W Storage Temperature Ts — -40 — +125 °C Mechanical Shock — Per Mil-STD-883D, Method 2002.3 — 500 — G’s Mechanical Vibration — Per Mil-STD-883D, Method 2007.2, 20-2000 Hz, Soldered in a PC board — 10 Weight — — — 11 *ISR will operate down to no load with reduced specifications. — — **See Thermal Derating chart. Note: The 78ST212 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications. Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com G’s Grams For assistance or to order, call 78ST212 CHARACTERISTIC (800) 531-5782 Series DATA (See Note 1) Efficiency vs Output Current 100 Efficiency (%) 90 Vin 80 15V 18V 21V 24V 28V 70 60 50 40 0.0 0.5 1.0 1.5 2.0 Iout (A) Ripple vs Output Current 60 Ripple (mV) 50 Vin 40 15V 18V 21V 24V 30 28V 20 10 0 0.0 0.5 1.0 1.5 2.0 Iout (A) Thermal Derating (Ta) (See Note 2) 2.0 60°C 70°C Iout (A) 1.5 85°C 1.0 0.5 0.0 14 16 18 20 22 24 26 28 Vin (Volts) Power Dissipation vs Output Current 3.0 PD (Watts) 2.5 Vin 2.0 15V 18V 21V 24V 28V 1.5 1.0 0.5 0.0 0.0 0.5 1.0 1.5 2.0 Iout (A) Note 1: All data listed in the above graphs, except for derating data, has been developed from actual products tested at 25°C. This data is considered typical data for the ISR. Note 2: Thermal derating graphs are developed in free air convection cooling of 40-60 LFM. (See Thermal Application Notes.) Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com DATA SHEETS 78ST212_ 12.0 VDC IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. 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