MIC2776 Micrel, Inc. MIC2776 Micro-Power Low Voltage Supervisor General Description Features The MIC2776 is a power supply supervisor which provides User-adjustable input can monitor supplies as low as under-voltage monitoring and power-on reset generation in a 0.3V compact 5-pin SOT package. Features include an adjustable 1.5% threshold accuracy under-voltage detector, a delay-generator, a manual reset Separate V input DD input, and a choice of active-high, active-low, or open-drain Generates power-on reset pulse (140ms min.) active-low reset output. The user-adjustable monitoring input Manual reset input is compared against a 300mV reference. This low reference Choice of active-high, active-low or open-drain active- voltage allows monitoring voltages lower than those supported low reset output by previous supervisor ICs. Inputs can be pulled above V (7V abs. max.) DD Open-drain output can be pulled above V (7V abs. The reset output is asserted for no less than 140ms at power- DD max.) on and any time the input voltage drops below the reference Ultra-low supply current, 3.0A typical voltage. It remains asserted for the timeout period after the Rejects brief input transients input voltage subsequently rises back above the threshold IttyBitty SOT-23-5 package boundary. A reset can be generated at any time by asserting the manual reset input, /MR. The reset output will remain ac- tive at least 140ms after the release of /MR. The /MR input Applications can also be used to daisy-chain the MIC2776 onto existing Monitoring processor, ASIC, or FPGA core voltage power monitoring circuitry or other supervisors. Hysteresis Computer systems is included to prevent chattering due to noise. Typical supply PDAs/Hand-held PCs current is a low 3.0A. Embedded controllers Telecommunications systems Power supplies Wireless / cellular systems Networking hardware Typical Application MICROPROCESSOR V 1.0V CORE VCORE VI/O V 2.5V I/O MIC2776L R1 VDD /RST /RESET GND IN R2 Power Good /MR GND Manual Reset IttyBitty is a trademark of Micrel, Inc. Micrel, Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 474-1000 MIC2776 Micrel, Inc Ordering Information Part Number Reset Output Temperature Range Package Standard Marking Pb-Free Marking MIC2776N-BM5 UKAA MIC2776N-YM5 UKAA Open-Drain, Active-Low / RST 40C to +85C SOT-23-5 MIC2776H-BM5 ULAA MIC2776H-YM5 ULAA Active-High, Complementary RST 40C to +85C SOT-23-5 MIC2776L-BM5 UMAA MIC2776L-YM5 UMAA Active-Low, Complementary /RST 40C to +85C SOT-23-5 Pin Conguration /MR GND /RST /MR GND RST 3 2 1 3 2 1 4 5 4 5 IN VDD IN VDD SOT-23-5 (M5) SOT-23-5 (M5) L and N Version H Version Pin Description Pin Number Pin Number Pin Name Pin Function MIC2776H MIC2776L MIC2776N 1 RST Digital (Output): Asserted high whenever V falls below the reference volt- IN age. It will remain asserted for no less than 140ms after V returns above IN the threshold limit. 1 /RST Digital (Output): Asserted low whenever V falls below the reference volt- IN age. It will remain asserted for no less than 140ms after V returns above IN the threshold limit. (open-drain for N version) 2 2 GND Ground 3 3 /MR Digital (Input): Driving this pin low initiates an immediate and unconditional reset. Assuming IN is above the threshold when /MR is released (returns high), the reset output will be de-asserted no less than 140ms later. /MR may be driven by a logic signal or a mechanical switch. /MR has an internal pull-up to V and may be left open if unused. DD 4 4 IN Analog (Input): The voltage on this pin is compared to the internal 300mV reference. An under-voltage condition will trigger a reset sequence. 5 5 VDD Analog (Input): Independent supply input for internal circuitry. MIC2776 2 November 2005