MIC845 Micro-Power Comparator / Battery Monitor General Description The MIC845 is a precision micro-power voltage comparator with an on-chip 2.55V reference voltage source. Teeny Intended for voltage monitoring applications, the Features MIC845 can be used with an external resistor divider Extremely low 1A supply current (typical) to detect a wide range of voltages, or without external resistors to directly monitor voltages with its 2.55V on chip reference high input impedance CMOS input. 2% voltage threshold accuracy The MIC845 incorporates a voltage reference and Optimized for PDAs, cellular telephones, pagers, comparator with fixed internal hysteresis. When the and other battery-powered devices 2.55V internal threshold is crossed, the output Open-drain output can be pulled up to 6V switches polarity. regardless of supply voltage MIC845 is available with a push-pull or open-drain 5-lead SC-70 package output stage. The push-pull output stage is configured for both active high or active low output Applications the open-drain output stage is only configured active high. PDAs Pagers Supply current is extremely low (typically 1A), making it ideal for portable applications. Cordless phones Portable electronics MIC845 is supplied in Micrels Teeny 5-lead SC- 70 package. Motherboards Bladed servers Data sheets and support documentation can be found on Micrels web site at www.micrel.com. Typical Applications 3.3V V V IN DD MIC845 MIC845 V V DD OUT V OUT DD Memory R1 INP OUT to Host power GND INP GND V = 2.55V REF Lithium Coin Cell 2.75V < V < 5.5V R2 DD Threshold Detector with Internal Fixed Hysteresis Nano-Power Battery Monitor Teeny 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 Micrel, Inc. MIC845 Ordering Information Part Number Temperature Range Package Standard Marking Pb-Free Marking* MIC845HBC5 B19 MIC845HYC5 B19 40 to +85C SC-70 MIC845LBC5 B20 MIC845LYC5 B20 40 to +85C SC-70 MIC845NBC5 B21 MIC845NYC5 B21 40 to +85C SC-70 * Note: Underscore on device marking indicates Pb-Free packaging. Pin Configuration INP GND NIC 1 3 2 4 5 OUT VDD SC-70-5 (C5) (TOP VIEW) Pin Description Pin Number Pin Name Pin Function 1 NIC No Internal Connection. A signal applied to this pin will have no effect on device operation. 2 GND Ground 3 INP Input: Analog input to the comparator. When V > V + V , V is INP REF HYST OUT asserted, and the condition is held until V < V . INP REF 4 OUT Output: Active-high, open-drain output. This output is low when V < V , indicating a low voltage input. The output is high when INP REF (N Version) V > V + V . INP REF HYST OUT Output: Active-high, Push-pull output. This output is low when V < V , indicating a low voltage condition. The output is high when INP REF (H Version) V > V + V . INP REF HYST OUT Output: Active-low, Push-pull output. This output is high when V < V , indicating a low voltage condition. The output is low when INP REF (L Version) V > V + V . INP REF HYST 5 VDD Power Supply (Input): Independent supply input for internal circuitry. M9999-070505 July 2005 2 (408) 955-1690