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. Intended for voltage monitoring applications, the MIC845 can be used with an external resistor divider to detect a wide range of voltages, or without external resistors to directly monitor voltages with its high input impedance CMOS input. The MIC845 incorporates a voltage reference and comparator with fixed internal hysteresis. When the 2.55V internal threshold is crossed, the output switches polarity. MIC845 is available with a push-pull or open-drain output stage. The push-pull output stage is configured for both active high or active low output; the open-drain output stage is only configured active high. Supply current is extremely low (typically 1µA), making it ideal for portable applications. MIC845 is supplied in Micrel’s Teeny™ 5-lead SC70 package. Data sheets and support documentation can be found on Micrel’s web site at www.micrel.com. Teeny™ Features • • • • Extremely low 1µA supply current (typical) 2.55V on chip reference ±2% voltage threshold accuracy Optimized for PDAs, cellular telephones, pagers, and other battery-powered devices • Open-drain output can be pulled up to 6V regardless of supply voltage • 5-lead SC-70 package Applications • • • • • • PDAs Pagers Cordless phones Portable electronics Motherboards Bladed servers ____________________________________________________________________________________________________ Typical Applications VIN 3.3V VDD MIC845 MIC845 VDD OUT Memory power R1 INP GND R2 Threshold Detector with Internal Fixed Hysteresis VDD VOUT VREF = 2.55V 2.75V < VDD < 5.5V Lithium Coin Cell INP OUT to Host GND 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 • http://www.micrel.com July 2005 M9999-070505 (408) 955-1690 Micrel, Inc. MIC845 Ordering Information Part Number Standard Marking Pb-Free Temperature Range Package Marking* MIC845HBC5 B19 MIC845HYC5 B19 –40° to +85°C SC-70 MIC845LBC5 B20 MIC845LYC5 B20 –40° to +85°C SC-70 MIC845NBC5 B21 MIC845NYC5 B21 –40° to +85°C SC-70 * Note: Underscore on device marking indicates Pb-Free packaging. Pin Configuration INP GND NIC 1 3 2 4 OUT 5 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 VINP > VREF+ VHYST, VOUT is asserted, and the condition is held until VINP < VREF. 4 OUT Output: Active-high, open-drain output. This output is low when VINP < VREF, indicating a low voltage input. The output is high when VINP > VREF + VHYST. (“N” Version) OUT (“H” Version) OUT 5 July 2005 Output: Active-high, Push-pull output. This output is low when VINP < VREF, indicating a low voltage condition. The output is high when VINP > VREF+ VHYST. (“L” Version) Output: Active-low, Push-pull output. This output is high when VINP < VREF, indicating a low voltage condition. The output is low when VINP > VREF+ VHYST. VDD Power Supply (Input): Independent supply input for internal circuitry. 2 M9999-070505 (408) 955-1690 Micrel, Inc. MIC845 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VDD) ..............................-0.3V to +6V Input Voltage (VINP).................................-0.3V to +6V Output Current (IOUT)......................................... 20mA Junction Temperature (TJ) .............. –40°C to +125°C Storage Temperature (Ts)............... –65°C to +150°C Lead Temperature (soldering, 5 sec.) ..............260°C ESD Rating(3) ........................................................3kV Supply voltage (VDD) ........................ +2.75V to +5.5V Input Voltage............................................... -0.3 to 6V Ambient Temperature (TA)................ –40°C to +85°C Junction to Ambient Thermal Resistance: SC-70 (θJA) ............................................ 450°C/W Electrical Characteristics 2.75V < VDD < 5.5V; TA = 25°C, Bold values indicate –40°C< TA < +85°C, unless noted. Parameter Parameter Conditions IDD Supply Current No load on output IINP Input Leakage Current VDD = 5.5V, VINP = 0V .005 10 nA IINP_PD Input Leakage Current in power down VDD = 0V (note 4), VINP = 5.5V .005 10 nA VREF VREF –40°C to 85°C 2.50 2.55 2.60 V VHYST Comparator Hysteresis 8 25 40 mV VOUT Output Voltage, ‘N’ ISINK = 1.6mA, VDD ≥ 2.75V 0.3 V VOUT Output Voltage, ‘L’ and ‘H’ ISINK = 1.6mA, VDD ≥ 2.75V 0.3 V ISOURCE = 500µA, VDD ≥ 2.75V tD Propagation Delay Min 0.95 × VDD Typ. Max Units 1 3 µA 0.99 × VDD V VINP = 2.7V to 2.4V 12 39 µs VINP = 2.4V to 2.7V 8 26 µs Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. Human body model: 1.5k in series with 100pF. 4. VDD is tied to Gnd, not left floating. July 2005 3 M9999-070505 (408) 955-1690 Micrel, Inc. MIC845 Typical Characteristics IDD vs. Temperature IIN vs. Temperature 1500 800 IDD (nA) 600 1000 VDD = 4.5V VIN = 0V 500 400 0 -500 200 -1000 0 VDD = 0V VIN = 4.5V -200 -40 -20 0 20 40 60 TEMPERATURE (°C) -2000 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 800 VDD = 3V VIN = 4.2V 600 IDD (nA) 800 400 200 VDD = 0V VIN = 4.2V -200 -40 -20 0 20 40 60 TEMPERATURE (°C) July 2005 VDD = 0V VIN = 4.2V 400 600 0 80 IIN vs. Temperature 1200 200 VDD = 4.5V VIN = 0V -1500 IDD vs. Temperature 1000 VDD = 0V VIN = 4.5V 0 VDD = 3V VIN = 4.2V -200 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 4 80 M9999-070505 (408) 955-1690 Micrel, Inc. MIC845 Block Diagrams VDD VDD 5 VIN VTH 3 OUT VDD 5 VIN High-Voltage Detect INP VTH VDD High-Voltage Detect INP 3 OUT 4 4 2.55V Bandgap Reference 2.55V Bandgap Reference 2 GND 2 GND MIC845L MIC845H VDD VIN VTH VDD 5 High-Voltage Detect INP OUT 4 3 2.55V Bandgap Reference 2 GND MIC845N VOUT VOUT VIN VIN VREF + Hysteresis VREF + Hysteresis VREF VREF Type L Type H and N July 2005 5 M9999-070505 (408) 955-1690 Micrel, Inc. MIC845 there will be no conduction from INP to VDD or any circuitry internal to MIC845. Application Information Output Input Transients The MIC845N output is an open-drain MOSFET, so most applications will require a pull-up resistor. It is recommended that the value of this resistor not exceed 470kΩ, otherwise PCB leakages may begin to dominate and give a false output indication. MIC845 is inherently immune to very short negative-going “glitches.” Very brief transients may exceed the VINP threshold without tripping the output. As shown in the figure below, the narrower the transient, the deeper the threshold overdrive that will be ignored by the MIC845. The graph represents the typical allowable transient duration for a given amount of threshold overdrive that will not generate an output. The output of “N” type devices may be pulled up as high as 6V regardless of the IC’s supply voltage, without damage to the IC. The “H” and “L” versions of MIC845 have push-pull output stages, no pull-up resistors are required. The maximum output voltage of the “H” and “L” versions is VDD. 16 Input 14 MIC845 has been designed to present an almost infinite input resistance at its INP pin making it ideal for monitoring lithium coin cell and back-up batteries. In applications where the ‘battery low’ voltage is 2.55V, MIC845’s INP pin may be tied directly to the cell’s positive terminal without any additional circuitry. 12 10 8 6 4 2 0 0 MIC845’s input may be subjected to voltages as high as 6V, steady-state, without any adverse effects, regardless of the IC’s supply voltage. This applies even if the supply voltage is zero. This permits a situation wherein the IC’s supply is turned off, but an input voltage is still present. Under such conditions, July 2005 Input Transient Response 6 200 400 600 800 1000 COMPARATOR OVERDRIVE VREF - VINP (mV) M9999-070505 (408) 955-1690 Micrel, Inc. MIC845 Package Information 0.65 (0.0256) BSC 1.35 (0.053) 2.40 (0.094) 1.15 (0.045) 1.80 (0.071) 2.20 (0.087) 1.80 (0.071) DIMENSIONS: MM (INCH) 1.00 (0.039) 1.10 (0.043) 0.80 (0.032) 0.80 (0.032) 0.30 (0.012) 0.15 (0.006) 0.10 (0.004) 0.00 (0.000) 0.18 (0.007) 0.10 (0.004) 0.30 (0.012) 0.10 (0.004) SC-70-5 (C5) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2005 Micrel, Inc. July 2005 7 M9999-070505 (408) 955-1690