MIC2777 Micrel, Inc. MIC2777 Dual Micro-Power Low Voltage Supervisor General Description Features The MIC2777 is a dual power supply supervisor that provides Monitors two independent power supplies for under-volt- under-voltage monitoring, manual reset capability, and power- age conditions on reset generation in a compact 5-pin SOT package. Fea- One xed and one user adjustable input tures include two under-voltage detectors, one xed and one 1.5% theshold accuracy adjustable, and both active-high and active-low reset outputs. Choice of factory-programmed thresholds One under-voltage detector compares V against a xed User-adjustable input can monitor supplies as low as DD threshold. Ten factory-programmed thresholds are available. 0.3V The other under-voltage detector is user-adjustable. Generates 140ms (minimum) power-on RESET pulse Manual reset capability The reset outputs are asserted for no less than 140ms at Both active-high and active-low RESET outputs power-on and any time V or the input voltage drops below DD Input may be pulled above V (abs. max.) the corresponding reference voltage. They remain asserted DD /RST output valid down to 1.2V for the timeout period after the input voltage and V sub- DD Ultra-low supply current, 3.5A typical sequently rise back above the threshold boundaries. A reset Rejects brief input transients can be generated at any time by pulling down on the adjust- IttyBitty 5-pin SOT-23 package able input. Hysteresis is included to prevent chattering due to noise. Typical supply current is a low 3.5A. Applications Monitoring processor, ASIC, or FPGA core and I/O volt- ages Computer systems PDAs, hand-held PCs Embedded controllers Telecommunications systems Power supplies Wireless / Cellular systems Networking hardware Ordering Information Part Number Junction Tem. Range Package Standard Marking Pb-Free Marking MIC2777-XXBM5 UNXX MIC2777-XXYM5 UNXX 40C to +85C SOT-23-5 Typical Application MICROPROCESSOR V 1.0V CORE V CORE V I/O V 1.8V I/O MIC2777 /RESET VDD /RST R1 GND IN RST R2 GND Manual Reset OTHER LOGIC Typical Application 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 MIC2777 Micrel, Inc. Standard Voltage Options* Voltage Typical Nominal Threshold Code Application (V ) Voltage (V ) DD TH 46 5.0V 5% 4.68 44 5.0V 10% 4.43 31 3.3V 5% 3.09 29 3.3V 10% 2.93 28 3.0V 5% 2.81 26 2.85V 5% 2.67 25 2.70V 5% 2.53 23 2.5V 5% 2.34 22 2.4V 5% 2.25 17 1.8V 5% 1.69 *There are ten standard versions available with an order increment of 3000 pieces. Samples of standard versions are normally available from stock. Contact factory for information on non-standard versions. Available in tape-and-reel only. Pin Conguration RST GND /RST 3 2 1 4 5 IN VDD SOT-23-5 (M5) Pin Description Pin Number Pin Name Pin Function 1 /RST Digital (Output): Asserted low whenever V or V falls below the reference IN DD voltage. It will remain asserted for no less than 140ms after V and V IN DD return above the threshold limits. 2 GND Ground 3 RST Digital (Output): Asserted high whenever V or V falls below the refer- IN DD ence voltage. It will remain asserted for no less than 140ms after V and IN V return within above the threshold limit. DD 4 IN Analog (Input): The voltage on this pin is compared to the internal 300mV reference. An undervoltage condition will trigger a reset sequence. Manual reset capability can be achieved by adding a switch between this pin and ground. 5 VDD Analog (Input): Power supply input for internal circuitry and input to the xed voltage monitor: The voltage on this pin is compared against the internal voltage reference. An undervoltage condition will trigger a reset sequence. MIC2777 2 November 2005