MAX1259CWE

MAX1259 Battery Manager General Description The MAX1259 battery manager provides backup-battery switching for CMOS RAM, microprocessors, or other lowpower logic ICs. It automatically switches to the backup battery when the primary power supply is interrupted. Low-loss switches guarantee an input-to-output differential of only 200mV while supplying 250mA from the primary power supply or 15mA from the battery. Battery discharge during shipping does not occur in the MAX1259, since the backup battery can be disconnected by strobing the RST input. A battery-fail output signal indicates when the backup battery is below +2V, and a power-fail output signal indicates when the primary power supply is low. The MAX1259 monitors the backup battery, warns of impending power failures, and switches the memory to the battery when failures occur. The MAX1259 is pincompatible with the DS1259, but consumes three times less supply current. Commercial, extended, and military temperature range devices are available. Applications ●● ●● ●● ●● Battery Backup for CMOS RAM Uninterruptible Power Supplies Computers Controllers Functional Diagram VCCI VCCO Features ●● Switches to Backup Battery if Power Fails ●● Consumes Less than 100nA of Battery Current ●● Power-Fail Output Signals Primary Power-Supply Loss ●● Battery Monitor Indicates Low Battery ●● Battery Can Be Disconnected to Prevent Discharge During Shipping ●● Battery Automatically Reconnected when VCC is Applied ●● Pin-Compatible with the DS1259 ●● Supply Current Three Times Lower than DS1259 ●● Available in Extended-Industrial and Military Temperature Ranges Ordering Information PART TEMP RANGE PIN-PACKAGE MAX1259C/D 0°C to +70°C Dice* MAX1259CPE 0°C to +70°C 16 PDIP MAX1259CWE 0°C to +70°C 16 Wide SO MAX1259EPE -40°C to +85°C 16 PDIP MAX1259EWE -40°C to +85°C 16 Wide SO MAX1259MJE -55°C to +125°C 16 CERDIP *Contact factory for dice specifications. Note: Devices in PDIP and SO packages are available in both leadedPb) and lead(Pb)-free packaging. Specify lead-free by adding the “+” symbol at the end of the part number when ordering. Lead-free not available for CERDIP package. Pin Configuration TOP VIEW N.C. 1 16 VCCI 15 VCCI VBATT VBATT RESET LOGIC 2 MAX1259 RST BF 3 14 N.C. N.C. 4 13 VCCO BAT 5 12 VCCO RST 6 11 PF GND 7 10 N.C. GND 8 9 N.C. PF BF REF MAX1259 BAT GND 19-4638; Rev 3; 9/14 DIP/SO MAX1259 Battery Manager Absolute Maximum Ratings Voltage on Any Pin (with respect to GND)............-0.3V to +7.0V Operating Temperature Range C Suffix................................................................0°C to +70°C E Suffix.............................................................-40°C to +85°C M Suffix..........................................................-55°C to +125°C Storage Temperature Range .............................-55°C to +125°C Lead Temperature (soldering, 10s) .................................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Recommended DC Operating Conditions (All grades, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER Primary Power Supply SYMBOL VCCI CONDITIONS Input Low Voltage VIH VIL TYP MAX UNITS 5.0 5.5 V 2.0 VCCI + 0.3 MAX1259E/M 2.4 VCCI + 0.3 MAX1259C Input High Voltage (Note 1) MIN (Note 1) (Note 1) -0.3 Battery Voltage VBATT Pin 2 (Note 2) 2.5 Battery Output BAT Pin 5 (Note 1) VBATT 0.1 3.0 V +0.8 V 3.7 V V DC Electrical Characteristics (VCC = +4.5V to +5.5V, all grades, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER Leakage Current SYMBOL CONDITIONS ILO VOH = 2.4V (Note 3) IOL VOL = 0.4V Input Supply Current ICCI (Note 4) VCCO Output Current ICCO VCCO = VCCI - 0.2V, pins 12, 13 Power-Fail Trip Point VTP Battery-Fail Trip Point VBATTF TYP -1.0 IOH Output Current PF, BF MIN MAX UNITS +1.0 µA -1.0 4.0 2.00 Pin 11 (Notes 2, 5) 1.26 x VBATT 250mV 1.26 x VBATT 3.33 mA 250 mA 1.26 x VBATT + 250mV V 2.0 Pin 3 (BF detect) (Note 6) mA V DC Electrical Characteristics (VCCI < VBATT, all grades, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER SYMBOL VCCO Output Current ICCO2 Battery Leakage (Note 8) IBATT BAT Output Current www.maximintegrated.com IBATOUT MAX UNITS VCCO = VBATT - 0.2V, pins 12, 13 (Note 7) CONDITIONS MIN TYP 15 mA MAX1259C 100 MAX1259E 150 MAX1259M 10 µA Pin 5 (Note 9) 100 µA nA Maxim Integrated │  2 MAX1259 Battery Manager Capacitance (All grades, TA = +25°C, unless otherwise noted.) (Note 10) PARAMETER SYMBOL Input Capacitance Output Capacitance CONDITIONS MIN TYP MAX UNITS CIN 5 10 pF COUT 5 10 pF TYP MAX UNITS AC Electrical Characteristics (VCC = 4.0V to 5.5V, all grades, TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN VCCI Fall Time tF 300 µs VCCI Rise Time tR 1 µs Power-Down to PF Low tPF 0 PF High After Power-Up tREC RST Pulse Width Note Note Note Note Note Note Note Note Note Note µs 100 RSTPW 50 10 µs ns 1: All voltages referenced to ground. 2: Trip-point voltage for power-fail detect: VTP = 1.26 x VBATT. For 5% operation: VBATT = 3.7V max. 3: 50pF load capacity. 4: Measured with pins 3, 11, 12, 13, and open. 5: VTP is the point at which PF is driven low. 6: VBATTF is the point at which BF is driven low. 7: ICCO2 may be limited by battery capacity. 8: Battery leakage is the internal energy consumed by the MAX1259. 9: See the Typical Operating Characteristics BAT Switch Drop vs. Battery Voltage graph. 10: Guaranteed by design. Not tested. Pin Description PIN NAME 1, 4, 9, 10, 14 N.C. 2 VBATT 3 BF Battery-Fail Output. BF is high for VCCI at or above VTP and the backup battery greater than 2V. If the backup battery is below 2V or VCCI falls below VTP, BF will be driven low. 5 BAT Battery Output. During normal operation, the BAT output supplies up to 1mA of continuous battery current. In shipping mode, the BAT output is high impedance. 6 RST Battery-Disconnect Input. The RST input is used to prevent battery discharge during shipping. Pulsing the RST input disconnects the backup battery from the VCCO and BAT outputs. 7, 8 GND Ground 11 PF Power-Fail Output. PF is high for VCCI greater than 1.26 x VBATT (VTP), indicating a valid VCCI voltage. 12, 13 VCCO CMOS RAM is Powered from VCCO. The battery switchover circuit compares VCCI to the VBATT input, and connects VCCO to whichever is higher. 15, 16 VCCI +5V VCC Input www.maximintegrated.com FUNCTION No Connection. Make no connection to these pins. Backup Battery Input Maxim Integrated │  3 MAX1259 Battery Manager Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) SWITCH VOLTAGE DROP vs. LOAD CURRENT VCCI = +4.5V 100 50 50 100 150 200 0 100 150 200 250 MAX1259toc03 5 10 SWITCH VOLTAGE DROP vs. LOAD CURRENT POWER-FAIL TRIP POINT vs. BATTERY VOLTAGE BATTERY-FAIL TRIP POINT vs. TEMPERATURE 50 VBATT = +3.0V 5 10 MAX1259toc05 4.6 4.4 4.2 VCCI RISING 4.0 3.8 3.6 VCCI FALLING 3.4 2.3 3.0 15 VCCI = 5.0V 2.2 2.1 VBATT RISING 2.0 1.9 1.8 VBATT FALLING 2.4 2.6 2.8 3.0 3.2 3.4 3.6 1.6 3.8 0 10 20 30 40 50 60 70 80 90 100 ICCO2 (mA) VBATT (V) TEMPERATURE (°C) QUIESCENT SUPPLY CURRENT vs. POWER SUPPLY BAT CURRENT vs. BATTERY VOLTAGE BAT SWITCH DROP vs. BATTERY VOLTAGE VBATT - BAT = 100mV 1.8 2.5 IBAT (mA) 1.6 2.0 1.5 TA = +25°C 1.4 1.2 1.0 TA = +75°C 0 1 2 3 VCCI (V) www.maximintegrated.com 4 5 6 0.8 2.0 2.5 3.0 VBATT (V) 3.5 4.0 IBAT = 1mA 80 60 40 20 1.0 0.5 100 VBATT - BAT (mV) VBATT = 3.0V, ICCO = 0mA TA = +25°C MAX1259toc08 2.0 MAX1259toc07 3.5 15 1.7 3.2 0 0 TA = +25°C 4.8 BATTERY-FAIL TRIP POINT (V) 100 5.0 POWER-FAIL TRIP POINT (V) MAX1259toc04 VBATT = +2.5V 0 0 ICCO2 (mA) 150 3.0 50 ICCO (mA) BATTERY-BACKUP MODE TA = +75°C VBATT - VCCO (mV) 250 0 ICCO (mA) 200 ICCI (mA) VBATT = +3.0V 0 0 VBATT = +2.5V 100 50 VCCI = +5.0V VCCI = +5.0V 0 150 MAX1259toc09 50 BATTERY-BACKUP MODE TA = +25°C VBATT - VCCO (mV) VCCI - VCCO (mV) VCCI - VCCO (mV) VCCI = +4.5V 100 VCC MODE TA = +75°C 150 200 MAX1259toc02 VCC MODE TA = +25°C 150 200 MAX1259toc01 200 SWITCH VOLTAGE DROP vs. LOAD CURRENT MAX1259toc06 SWITCH VOLTAGE DROP vs. LOAD CURRENT 0 IBAT = 100µA 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 VBATT (V) Maxim Integrated │  4 MAX1259 Battery Manager VCCI +4.25V +3V tF tR tPF PF tREC BATTERY CURRENT Figure 1. Power-Down/Power-Up Conditions Detailed Description Battery Switchover and VCCO Figure 2 shows a typical application for the MAX1259. CMOS RAM is powered from VCCO. The battery switchover circuit compares VCC to the VBATT input, and connects VCCO to whichever is higher. Switchover occurs when VCC equals VBATT as VCC falls, and when VCC is 60mV greater than VBATT as VCC rises. This hysteresis prevents repeated, rapid switching if VCC falls very slowly or remains nearly equal to the battery voltage. Low-loss switches guarantee an input-to-output differential of only 200mV, while supplying 250mA from the primary power supply or 15mA from the battery. Note: With adequate filtering, the MAX1259 need only supply the average current drawn by the CMOS RAM. Many RAM data sheets specify a 75mA maximum supply current, but this peak current spike lasts only 100ns. If the sum of the peak currents is greater than 250mA, a capacitor placed on the VCCO output can supply the high instantaneous current, while VCCO need only supply the average current, which is much less. The MAX1259 operates with battery voltages from 2.5V to 3.7V. High-value capacitors—either standard electrolytic or farad-sized, double-layer capacitors—can also be used for short-term memory backup (Figure 3). 15, 16 VCC VCCI VCC0 12, 13 TO RAM RAM16 3kΩ RAM2 VCC 15, 16 VCCO VCCI MAX1259 2 PF VBATT CE1 12, 13 2N3904 CE0 6.2kΩ 11 NMI GND 7, 8 Figure 2. Typical Application Circuit www.maximintegrated.com MAX1259 CE15 RAM1 ADDRESS DECODE 0.22F MAXCAP 2 VBATT GND 7, 8 µP NOTE: LARGE VALUE CAPACITORS, SUCH AS A 0.22F MAXCAP, MAY BE USED FOR SHORT-TERM MEMORY BACKUP. Figure 3. Using a MAXCAP as a Backup Battery Maxim Integrated │  5 MAX1259 Battery Manager +5V VCCI 0V 50ns MIN RST VIH VIL +5V VCCO +3V HIGH IMPEDANCE 0V BAT +3V HIGH IMPEDANCE 0V Figure 4. Reset Timing To achieve rated performance, the VCC input should be connected to both VCCI pins (pins 15 and 16). As well, the switched output should be connected to both VCCO pins (pins 12 and 13). RESET (Digitally Controlled Battery Disconnect) Power Fail If VCCI is at or above the voltage trip threshold (VTP) and the backup battery is greater than 2V, the battery-fail (BF) output will be held high, indicating a charged battery. If the backup battery drops below 2V or VCCI falls below VTP, BF will be driven low. This disconnect feature is activated by pulsing the reset (RST) input high for a minimum of 50ns with VCCI greater than VTP (Figure 4). When primary power is removed, the VCCO and BAT outputs will go high impedance. The next time primary power is applied with VCCI greater than 1.26 x VBATT (VTP), normal operation resumes. Note that when the MAX1259 is first powered up, VCCI must be brought above 1.26 x VBATT. This resets an internal flipflop, ensuring that the part is in normal VCC mode and not in shipping mode. BAT Output Applications Information The power-fail (PF) output is high for VCCI greater than 1.26 x VBATT (VTP), indicating a valid VCCI voltage. Battery Fail During normal operation, the BAT output stays at the battery voltage, regardless of the VCCI level. This provides 1mA battery current. www.maximintegrated.com To prevent battery discharge during shipping, the backup battery can be disconnected from VCCO to BAT. If a protection diode is placed in series with the backup battery, pin 2 must be bypassed with at least a 0.01μF capacitor to ground. Maxim Integrated │  6 MAX1259 Chip Topography Battery Manager Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE www.maximintegrated.com PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 16 PDIP P16+2 21-0043 — 16 Wide SO W16+2 21-0042 90-0107 16 CERDIP J16-3 21-0045 — Maxim Integrated │  7 MAX1259 Battery Manager Revision History REVISION NUMBER REVISION DATE 3 9/14 DESCRIPTION Removed automotive reference from Applications PAGES CHANGED 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. ©  2014 Maxim Integrated Products, Inc. │  8