A8450 Automotive Multioutput Voltage Regulator Features and Benefits Description 6 V to 45 V input range The A8450 is a multioutput power supply intended for DC-to-DC buck converter with 5.7 V output automotive applications. The A8450 operates from a wide Overcurrent protection with foldback, and undervoltage input supply range and is designed to satisfy the requirements lockout (UVLO) of high ambient temperature environments. Dual 5 V outputs Four regulated voltage outputs provide multiple options. The Digital 5 V 2%, 200 mA 3.3 V regulator and the 1.2 to 3.3 V adjustable regulator can be Analog 5 V, 200 mA used to power microcontroller or DSP cores, or for I/O, sensing, Short-to-supply protection on analog regulator and A-to-D conversion. Two 5 V outputs, one digital and the Analog to digital regulator output tracking < 0.5% other analog, feature output tracking within 0.5% of each other throughout operating temperature range over the operating temperature range. In addition, the analog regulator is protected against short-to-battery conditions. All four regulators feature foldback current limit protection. Continued on the next page The device can be enabled or disabled using two input pins. The high voltage input, on the ENBAT pin, allows enable/ Package: 24 pin SOIC (suffix LB) disable using an engine ignition or battery switch signal. The logic-level input, on the ENB pin, allows enable/disable by microcontroller or DSP signals. When disabled, the A8450 draws less than 10 A of current. A POR (power-on-reset) block monitors the supply voltages and provides a reset signal, with an adjustable delay, for Continued on the next page Not to scale Typical Application H.V. L1 VIN D2 LX VBB D1 C8 CIN ENBAT CP2 COUT CP1 V33 Q1 C3 VCP V33BD C7 VREG11 CL33 C10 R3 GND GND A8450 GND GND ENB VREG CPOR V5D C1 C9 CLADJ NFAULT Q2 R4 NPOR VADJBD VADJ R1 FB V5A R2 C2 C4 A8450-DS, Rev. 8A8450 Automotive Multioutput Voltage Regulator Features and Benefits (continued) Description (continued) microcontroller or DSP resets. A separate fault pin signals TSD 3.3 V linear regulator, with foldback current limit (thermal shutdown), 5 V analog short-to-supply, and 5 V analog or Adjustable 1.2 V to 3.3 V linear regulator, adjustable foldback digital undervoltage. current limit The A8450 is supplied in a 24-pin SOIC-W package (part number Ignition switch enable Sleep mode suffix LB) with internally-fused power ground pins for enhanced 100% duty cycle operation for low input voltages thermal performance. This provides an R of 35C/W on a 4-layer JA Power OK output board (see chart on p. 5). The lead (Pb) free version has 100% matte 40C to 135C ambient operating temperature range tin leadframe plating. Selection Guide Part Number Pb-free Packing Terminals Package SOIC-W surface mount, internally A8450KLBTR-T Yes 1000 pieces per 13-in. reel 24 fused power ground pins (6-7, 18-19) Absolute Maximum Ratings Parameter Symbol Conditions Rating Units Load Supply Voltage V VBB pin 40 V BB Analog Output V V5A pin 1 to 45 V 5A V ENBAT pin input 0.3 to 45 V ENBAT Logic Input Signal V ENB pin input 0.3 to 6.5 V ENB LX Voltage V LX pin 2 to V V LX BB Operating Temperature Range T K range 40 to 135 C A Junction Temperature T (max 150 C J ) Storage Temperature Range T 55 to 150 C stg Allegro MicroSystems, LLC 2 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000 www.allegromicro.com