19-3774; Rev 2; 1/06 Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages The MAX6775–MAX6781 low-power, 1%-accurate battery monitors are available in the ultra-small µDFN package (1.0mm x 1.5mm) and SC70 packages. These low-power devices are ideal for monitoring single lithium-ion (Li+) cells, or multicell alkaline/NiCd/NiMH power sources. These devices offer single (MAX6775/ MAX6776/MAX6777/MAX6778) or dual (MAX6779/ MAX6780/MAX6781) low-battery outputs and feature fixed or resistor-adjustable hysteresis. Hysteresis eliminates the output chatter sometimes associated with battery voltage monitors, usually due to input-voltage noise or battery terminal voltage recovery after load removal. These devices are available in several versions: with single- or dual-voltage monitors, and with fixed or adjustable hysteresis. The MAX6775/MAX6776 offer a single battery monitor and factory-set hysteresis of 0.5%, 5%, or 10%. The MAX6779/MAX6780/MAX6781 have two battery monitors in a single package and factory-set hysteresis of 0.5%, 5%, or 10%. The MAX6777/ MAX6778 offer a single battery monitor with external inputs for the rising and falling thresholds, allowing external hysteresis control. For convenient interface with system power circuitry or microprocessors, both open-drain and push-pull outputs are available. The single-channel devices are available with open-drain or push-pull outputs. The dual-channel devices are available with both outputs open-drain, both outputs push-pull, or one of each (see the Selector Guide). This family of devices is offered in small 5-pin SC70 and ultra-small 6-pin µDFN packages, and is fully specified over the -40°C to +85°C extended temperature range. Features ♦ 1.0%-Accurate Threshold Specified Over Temperature ♦ ♦ ♦ ♦ ♦ Single/Dual, Low-Battery Output Options Low 3µA Battery Current Open-Drain or Push-Pull Low-Battery Outputs Fixed or Adjustable Hysteresis Low-Input Leakage Current Allows Use of Large Resistors ♦ Guaranteed Valid Low-Battery-Output Logic State Down to VBATT = 1V ♦ Immune to Short Battery Transients ♦ Fully Specified from -40°C to +85°C ♦ Small 5-Pin SC70 or Ultra-Small 6-Pin µDFN (1mm x 1.5mm) Package Ordering Information TEMP RANGE PIN-PACKAGE MAX6775XK_+T PART -40°C to +85°C 5 SC70-5 MAX6775LT_+T* -40°C to +85°C 6 µDFN-6 MAX6776XK_+T -40°C to +85°C 5 SC70-5 MAX6776LT_+T -40°C to +85°C 6 µDFN-6 MAX6777XK+T -40°C to +85°C 5 SC70-5 MAX6777LT+T -40°C to +85°C 6 µDFN-6 Ordering Information continued at end of data sheet. +Denotes lead-free package. *Future product—contact factory for availability. MAX6775/MAX6776/MAX6779/MAX6780/MAX6781 are available with factory-trimmed hysteresis. Specify trim by replacing “_” with “A” for 0.5%, “B” for 5%, or “C” for 10% hysteresis. Typical Operating Circuit Applications Battery-Powered Systems (Single-Cell Li+ or Multicell NiMH, NiCd, Alkaline) Cell Phones/Cordless Phones Pagers BATT IN Portable Medical Devices DC-DC CONVERTER MAX6775 PDAs Electronic Toys 3.6V LBI LBO SHDN OUT MP3 Players Pin Configurations appear at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX6775–MAX6781 General Description MAX6775–MAX6781 Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages ABSOLUTE MAXIMUM RATINGS BATT to GND............................................................-0.3V to +6V LBI, LBL, LBH, LBI1, LBI2 to GND ...............-0.3V to minimum of ((VBATT + 0.3V) and +6V) LBO, LBO1, LBO2 to GND (open-drain) .................-0.3V to +6V LBO, LBO1, LBO2 to GND (push-pull).........-0.3V to minimum of ((VBATT + 0.3V) and +6V) Input Current (all pins) ........................................................20mA Output Current (all pins) .....................................................20mA Continuous Power Dissipation (TA = +70°C) 5-Pin SC70 (derate 3.1mW/°C above +70°C) ..............247mW 6-Pin µDFN (derate 2.1mW°C above +70°C) ..............168mW Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°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. ELECTRICAL CHARACTERISTICS (VBATT = 1.6V to 5.5V, TA = -40°C to +85°C, unless otherwise specified. Typical values are at TA = +25°C.) (Note 1) PARAMETER Operating Voltage Range (Note 2) Supply Current SYMBOL VBATT IQ CONDITIONS MIN TYP MAX TA = 0°C to +70°C 1.0 5.5 TA = -40°C to +85°C 1.2 5.5 VBATT = 3.7V, no load 4 7 VBATT = 1.8V, no load 3.2 6 UNITS V µA FIXED HYSTERESIS (MAX6775/MAX6776/MAX6779/MAX6780/MAX6781) LBI, LBI_ Falling Threshold (Note 3) VLBIF LBI Rising Threshold VLBIR LBI Input Leakage Current 0.5% hysteresis version 1.2037 1.2159 1.2280 5% hysteresis version 1.1493 1.1609 1.1725 10% hysteresis version 1.0888 1.0998 1.1108 1.2098 1.222 1.2342 V +5 nA 1.2342 V +5 nA 0.2V ≤ VLBI ≤ VBATT - 0.2V -5 V ADJUSTABLE HYSTERESIS (MAX6777/MAX6778) LBL, LBH Threshold VBATT = 1.8V to 5.5V LBL, LBH Input Leakage Current VBATT - 0.2V ≥ VLBL/LBH ≥ 0.2V 2 1.2098 1.222 -5 _______________________________________________________________________________________ Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages (VBATT = 1.6V to 5.5V, TA = -40°C to +85°C, unless otherwise specified. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 3 ms LOW-BATTERY OUTPUTS (LBO, LBO1, LBO2) Propagation Delay tPD Startup Time VLBI_ + 100mV to VLBI_ - 100mV 9 µs VBATT rising above 1.6V Output Low (Push-Pull or Open-Drain) VOL Output High (Push-Pull ) VOH Output Leakage Current (Open-Drain) VBATT ≥ 1.2V, ISINK = 100µA 0.3 VBATT ≥ 2.7V, ISINK = 1.2mA 0.3 VBATT ≥ 4.5V, ISINK = 3.2mA 0.3 VBATT ≥ 1.6V, ISOURCE = 100µA 0.8 x VBATT VBATT ≥ 2.7V, ISOURCE = 500µA 0.8 x VBATT VBATT ≥ 4.5V, ISOURCE = 800µA 0.8 x VBATT Output not asserted, VLBO_ = 5.5V V V -100 +100 nA Note 1: Devices are tested at TA = +25°C and guaranteed by design for TA = TMIN to TMAX, as specified. Note 2: Operating range ensures low-battery output is in the correct state. Minimum battery voltage for electrical specification is 1.6V. Note 3: The rising threshold is guaranteed to be higher than the falling threshold. Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) 4.5 4.0 3.5 VBATT = 2.4V VBATT = 1.6V 3.0 11 10 VBATT = 5V 9 8 100mV OVERDRIVE 2.5 -40 -15 10 35 TEMPERATURE (°C) 60 85 7 -40 -15 10 35 TEMPERATURE (°C) 60 70 MAXIMUM TRANSIENT DURATION (µs) VBATT = 1.6V PROPAGATION DELAY (µs) VBATT = 5V VBATT = 3.6V VBATT = 3V MAX6775 toc02 5.5 SUPPLY CURRENT (µA) 12 MAX6775 toc01 6.0 5.0 MAXIMUM TRANSIENT DURATION vs. THRESHOLD OVERDRIVE PROPAGATION DELAY vs. TEMPERATURE OUTPUT ASSERTED ABOVE THIS LINE 60 MAX6775 toc03 SUPPLY CURRENT vs. TEMPERATURE 50 40 30 20 10 0 85 1 10 100 1000 THRESHOLD OVERDRIVE VTH - VCC (mV) _______________________________________________________________________________________ 3 MAX6775–MAX6781 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) RISING -1 FALLING -2 -3 0 1 RISING FALLING -1 -2 -3 -4 -5 -4 -40 -15 10 35 60 85 -15 TEMPERATURE (°C) 10 35 60 85 0 FALLING RISING -1 -2 -40 -15 TEMPERATURE (°C) VBATT = 3.3V 0.4 35 LBO OUTPUT VOLTAGE vs. SOURCE CURRENT 5.5 MAX6775 toc07 VBATT = 1.8V 10 TEMPERATURE (°C) LBO OUTPUT VOLTAGE vs. SINK CURRENT 5.0 VBATT = 5.0V 4.5 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) NORMALIZED AT TA = +25°C -3 -40 0.5 0.3 0.2 VBATT = 5.0V 4.0 VBATT = 3.3V 3.5 3.0 2.5 VBATT = 1.8V 2.0 0.1 1.5 0 1.0 0 3 6 9 SINK CURRENT (mA) 4 12 MAX6775 toc06 NORMALIZED AT TA = +25°C MAX6775 toc08 0 THRESHOLD VOLTAGE (mV) NORMALIZED AT TA = +25°C NORMALIZED THRESHOLD VOLTAGES vs. TEMPERATURE, MAX67__C THRESHOLD VOLTAGE (mV) 1 MAX6775 toc04 1 NORMALIZED THRESHOLD VOLTAGES vs. TEMPERATURE, MAX67__B MAX6775 toc05 NORMALIZED THRESHOLD VOLTAGES vs. TEMPERATURE, MAX67__A THRESHOLD VOLTAGE (mV) MAX6775–MAX6781 Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages 15 0 1 2 3 4 SOURCE CURRENT (mA) _______________________________________________________________________________________ 5 60 85 Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages MAX6775/ MAX6776 MAX6777/ MAX6778 MAX6779/ MAX6780/ MAX6781 NAME FUNCTION µDFN SC70 µDFN SC70 µDFN 1 1 — — — GND2 Reserved. Must be connected to GND. Do not use as the only GND connection. 2 2 2 2 2 GND Ground 3 3 — — — LBI Low-Battery Input. Connect to the resistive divider to set the trip level. 4 4 4 4 — LBO Low-Battery Output, Active-Low. When VLBI/VLBL falls below the falling threshold, LBO asserts. LBO deasserts when VLBI/VLBH exceeds the rising threshold voltage. 5 — 5 — — N.C. No Connection. Not internally connected. 6 5 6 5 6 BATT Battery Input. Power supply to the device. — — 1 1 — LBH Rising-Trip-Level Input. Connect to a resistive divider to set the rising trip level. — — 3 3 — LBL Falling-Trip-Level Input. Connect to a resistive divider to set the falling trip level. — — — — 1 LBI2 Low-Battery Input 2. Connect to a resistive divider to set the trip level. — — — — 3 LBI1 Low-Battery Input 1. Connect to a resistive divider to set the trip level. LBO1 Low-Battery Output 1, Active-Low. When VLBI1 falls below the falling threshold voltage, LBO1 asserts. LBO1 deasserts when VLBI1 exceeds the rising threshold voltage. LBO1 is push-pull on the MAX6779/MAX6781 and open-drain for the MAX6780. LBO2 Low-Battery Output 2, Active-Low. When VLBI2 falls below the falling threshold voltage, LBO2 asserts. LBO2 deasserts when VLBI2 exceeds the rising threshold voltage. LBO2 is open-drain for the MAX6780/MAX6781 and push-pull for the MAX6779. — — — — — — — — 4 5 _______________________________________________________________________________________ 5 MAX6775–MAX6781 Pin Description MAX6775–MAX6781 Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages Detailed Description These battery monitors have an active-low output that asserts when the input falls below a set voltage. They also offer hysteresis for noise immunity, and to remove the possibility of output chatter due to battery terminal voltage recovery after load removal. They are available with one or two monitors per package, with push-pull or open-drain outputs, and with internally set or externally adjustable hysteresis (dual-channel devices offer only internally fixed hysteresis). Figures 1, 2, and 3 show block diagrams and typical connections. See the Selector Guide for details. VBATT BATT MAX6779 MAX6780 MAX6781 LBI1 LBO1 1 HYSTERESIS CONTROL Low-Battery Output All devices are offered with either push-pull or opendrain outputs (see the Selector Guide). The MAX6781 has one push-pull output and one open-drain output, configured as in Table 1. 0 VREF 0 LBO2 On all devices with open-drain outputs an external pullup resistor is required. The open-drain pullup resistor can connect to an external voltage up to +6V, regardless of the voltage at BATT. 1 LBI2 GND Table 1. MAX6781 Outputs DEVICE LBO1 LBO2 MAX6781 Push-Pull Open-Drain VBATT Figure 2. Dual-Channel Fixed-Hysteresis Block Diagram VBATT BATT BATT RH RH MAX6777 MAX6778 MAX6775 MAX6776 LBI RL HYSTERESIS CONTROL 1 LBO LBL 1 LBH 0 RHYST LBO 0 VREF GND Figure 1. Single-Channel Fixed-Hysteresis Block Diagram 6 RL VREF GND Figure 3. Single-Channel Adjustable-Hysteresis Block Diagram _______________________________________________________________________________________ Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages Hysteresis Input hysteresis defines two thresholds, separated by a small voltage (the hysteresis voltage), configured so the output asserts when the input falls below the falling threshold, and deasserts only when the input rises above the rising threshold. Figure 4 shows this graphically. Hysteresis removes, or greatly reduces, the possibility of the output changing state in response to noise or battery terminal voltage recovery after load removal. Fixed Hysteresis The MAX6775/MAX6776/MAX6779/MAX6780/MAX6781 have factory-set hysteresis for ease of use, and reduce component count. For these devices, the absolute hysteresis voltage is a percentage of the internally generated reference. The amount depends on the device option. “A” devices have 0.5% hysteresis, “B” devices have 5% hysteresis, and “C” devices have 10% hysteresis. Table 2 presents the threshold voltages for devices with internally fixed hysteresis. MAX6775 MAX6776 VBATT Adjustable Hysteresis The MAX6777/MAX6778 offer external hysteresis control through the resistive divider that monitors battery voltage. Figure 3 shows the connections for external hysteresis. See the Calculating an External Hysteresis Resistive Divider section for more information. Applications Information Resistor-Value Selection Choosing the proper external resistors is a balance between accuracy and power use. The input to the voltage monitor, while high impedance, draws a small current, and that current travels through the resistive divider, introducing error. If extremely high resistor values are used, this current introduces significant error. With extremely low resistor values, the error becomes negligible, but the resistive divider draws more power from the battery than necessary and shortens battery life. Figure 1 calculates the optimum value for RH using: RH = where eA is the maximum acceptable absolute resistive divider error (use 0.01 for 1%), VBATT is the battery voltage at which LBO should activate, and IL is the worstcase LBI leakage current. For example, with 0.5% accuracy, a 2.8V battery minimum, and 5nA leakage, RH = 2.80MΩ. Calculate RL using: VLBIR RL = VHYST VLBIF tPD eA x VBATT IL − VLBIF x RH VLBIF − VBATT where VLBIF is the falling threshold voltage from Table 2. Continuing the above example, select VLBIF = 1.0998V (10% hysteresis device) and RL = 1.81MΩ. tPD LBO Figure 4. Hysteresis Table 2. Typical Falling and Rising Thresholds for MAX6775/MAX6776/MAX6779/MAX6780/MAX6781 DEVICE OPTION PERCENT HYSTERESIS (%) FALLING THRESHOLD (VLBIF) (V) RISING THRESHOLD (VLBIR) (V) HYSTERESIS VOLTAGE (VHYST) (mV) A 0.5 1.2159 1.222 6.11 B 5 1.1609 1.222 61.1 C 10 1.0998 1.222 122 _______________________________________________________________________________________ 7 MAX6775–MAX6781 The MAX6779, MAX6780, and MAX6781 monitor two battery levels or two independent voltages. A common application for this type of dual-battery monitor is to use one output as an early warning signal and the other as a dead-battery indicator. MAX6775–MAX6781 Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages Calculating an External Hysteresis Resistive Divider Setting the hysteresis externally requires calculating three resistor values, as indicated in Figure 3. First calculate RH using: RH = eA x VBATT IL − (as in the above example). Where RL0 equals RL + R HYST , determine the total resistor-divider current, ITOTAL, at the trip voltage using: VBATT RH + RL0 RL = RL0 - RHYST Monitoring a Battery Voltage Higher Than the Allowable VBATT Adding External Capacitance to Reduce Noise and Transients VLBIR x RH VLBIR − VBATT I TOTAL = Finally, determine RL using: For monitoring higher voltages, supply power to BATT that is within the specified supply range, and power the input resistive divider from the high voltage to be monitored. Do not exceed the Absolute Maximum Ratings. and RL0 using: RL0 = where VHYST is the required hysteresis voltage. If monitoring voltages in a noisy environment, add a bypass capacitor of 0.1µF from BATT to GND as close as possible to the device. For systems with large transients, additional capacitance may be required. A small capacitor (<1nF) from LBI_ to GND may provide additional noise immunity. Then, determine RHYST using: RHYST = VHYST I TOTAL Selector Guide LBO OUTPUT OUTPUT TYPE HYSTERESIS MAX6775XK_+T Single Push-Pull Fixed 5 SC70-5 MAX6775LT_+T Single Push-Pull Fixed 6 µDFN-6 PART 8 PIN-PACKAGE MAX6776XK_+T Single Open-Drain Fixed 5 SC70-5 MAX6776LT_+T Single Open-Drain Fixed 6 µDFN-6 MAX6777XK+T Single Push-Pull Adjustable 5 SC70-5 MAX6777LT+T Single Push-Pull Adjustable 6 µDFN-6 MAX6778XK+T Single Open-Drain Adjustable 5 SC70-5 MAX6778LT+T Single Open-Drain Adjustable 6 µDFN-6 MAX6779LT_+T Dual Push-Pull Fixed 6 µDFN-6 MAX6780LT_+T Dual Open-Drain Fixed 6 µDFN-6 MAX6781LT_+T Dual Mixed Fixed 6 µDFN-6 _______________________________________________________________________________________ Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages PART TOP MARK PART TOP MARK ASD ASA MAX6777XK+T MAX6775XKB+T ASB MAX6777LT+T CB MAX6775XKC+T ASC MAX6778XK+T ASI MAX6775LTA+T BU MAX6778LT+T CC MAX6775LTB+T BW MAX6779LTA+T BL MAX6775LTC+T BX MAX6779LTB+T BM MAX6776XKA+T ASJ MAX6779LTC+T BN MAX6776XKB+T ASK MAX6780LTA+T BO MAX6776XKC+T ASL MAX6780LTB+T BP BQ MAX6775XKA+T BY MAX6780LTC+T MAX6776LTB+T BZ MAX6781LTA+T BR MAX6776LTC+T CA MAX6781LTB+T BS MAX6781LTC+T BT MAX6776LTA+T Ordering Information (continued) PART TEMP RANGE PIN-PACKAGE MAX6778XK+T -40°C to +85°C 5 SC70-5 MAX6778LT+T -40°C to +85°C 6 µDFN-6 MAX6779LT_+T -40°C to +85°C 6 µDFN-6 MAX6780LT_+T -40°C to +85°C 6 µDFN-6 MAX6781LT_+T -40°C to +85°C 6 µDFN-6 Chip Information PROCESS: BICMOS TRANSISTOR COUNT: 496 +Denotes lead-free package. MAX6775/MAX6776/MAX6779/MAX6780/MAX6781 are available with factory-trimmed hysteresis. Specify trim by replacing “_” with “A” for 0.5%, “B” for 5%, or “C” for 10% hysteresis. _______________________________________________________________________________________ 9 MAX6775–MAX6781 Top Marks Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages MAX6775–MAX6781 Pin Configurations TOP VIEW BATT N.C. LBO 6 5 4 + GND2 1 5 BATT MAX6775 MAX6776 GND 2 LBI 3 MAX6775 MAX6776 4 LBO 1 SC70-5 GND2 2 3 GND LBI µDFN-6 BATT N.C. LBO BATT LBO2 LBO1 6 5 4 6 5 4 + LBH 1 GND 2 5 BATT MAX6777 MAX6778 LBL 3 4 LBO 1 SC70-5 LBH 2 3 1 GND LBL LBI2 µDFN-6 10 MAX6779 MAX6780 MAX6781 MAX6777 MAX6778 2 3 GND LBI1 µDFN-6 ______________________________________________________________________________________ Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages 6L UDFN.EPS 3 e A b 5 4 6 TOPMARK 2 AAA PIN 1 INDEX AREA PIN 1 0.075x45° L2 L E 3 1 A1 D SIDE VIEW TOP VIEW A 1 BOTTOM VIEW b SECTION A-A 2 A L1 COMMON DIMENSIONS MIN. 0.64 -1.45 0.95 0.30 --0.17 A A1 D E L L1 L2 b e NOM. 0.72 0.20 1.50 1.00 0.35 --0.20 0.50 BSC. MAX. 0.80 -1.55 1.05 0.40 0.08 0.05 0.23 TITLE: PACKAGE OUTLINE, 6L uDFN, 1.5x1.0x0.8mm APPROVAL -DRAWING NOT TO SCALE- DOCUMENT CONTROL NO. 21-0147 REV. C 1 ______________________________________________________________________________________ 1 11 MAX6775–MAX6781 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) SC70, 5L.EPS MAX6775–MAX6781 Low-Power, 1%-Accurate Battery Monitors in µDFN and SC70 Packages PACKAGE OUTLINE, 5L SC70 21-0076 C 1 1 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2006 Maxim Integrated Products Heaney Printed USA is a registered trademark of Maxim Integrated Products, Inc.