19-0541; Rev 3; 3/10 Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages Features o 1% Accurate Threshold Specified Over Full Temperature Range o Dual-/Triple-/Quad, Low-Battery Output Options o Low 5.7µA Battery Current o Open-Drain or Push-Pull Outputs o Fixed or Adjustable Hysteresis The MAX6782/MAX6783 offer four battery monitors in a single package with factory-set (0.5%, 5%, 10%) or adjustable hysteresis. The MAX6784/MAX6785 provide three battery monitors with factory-set (0.5%, 5%, 10%) or adjustable hysteresis. The MAX6786/MAX6787/ MAX6788 offer two battery monitors with external inputs for setting the rising and falling thresholds, allowing external hysteresis control. The MAX6789/MAX6790 feature quad-level overvoltage detectors with complementary outputs. The MAX6782–MAX6790 are offered with either open-drain or push-pull outputs. The MAX6782/MAX6784/MAX6786/ MAX6789 are available with push-pull outputs while the MAX6783/MAX6785/MAX6787/MAX6790 are available with open-drain outputs. The MAX6788 is available with one open-drain output and one push-pull output (see the Selector Guide). This family of devices is offered in spacesaving TDFN and TQFN packages and is fully specified over the -40°C to +85°C extended temperature range. o Low Input Bias Current o Guaranteed Valid Low-Battery-Output Logic State Down to VBATT = 1.05V o Reverse-Battery Protection o Immune to Short Battery Transients o Fully Specified from -40°C to +85°C o Small TDFN and TQFN Packages Ordering Information PART PIN-PACKAGE -40°C to +85°C 16 TQFN-EP* MAX6783TE_+ -40°C to +85°C 16 TQFN-EP* MAX6784TC_+ -40°C to +85°C 12 TQFN-EP* MAX6785TC_+ -40°C to +85°C 12 TQFN-EP* Ordering Information continued at end of data sheet. +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. The MAX6782/MAX6783/MAX6784/MAX6785 are available with factory-trimmed hysteresis. Specify trim by replacing “_” with “A” for 0.5%, “B” for 5%, or “C” for 10% hysteresis. Applications Battery-Powered Systems (Single-Cell Li+ or Multicell NiMH, NiCd, Alkaline) Cell Phones/Cordless Phones TEMP RANGE MAX6782TE_+ Pagers Portable Medical Devices PDAs Electronic Toys MP3 Players Pin Configuration and Typical Operating Circuit appear at end of data sheet. Selector Guide MONITOR LEVEL LBO OUTPUT OV OV OUTPUT TYPE HYSTERESIS MAX6782TE_+ 4 Quad — — Push-Pull Fixed/Adj MAX6783TE_+ 4 Quad — — Open Drain Fixed/Adj MAX6784TC_+ 3 Triple — — Push-Pull Fixed/Adj MAX6785TC_+ 3 Triple — — Open Drain Fixed/Adj MAX6786TA+ 2 Dual — — Push-Pull Adj MAX6787TA+ 2 Dual — — Open Drain Adj MAX6788TA+ 2 Dual — — Push-Pull/Open Drain Adj MAX6789TB+ 4 — Single Single Push-Pull — MAX6790TB+ 4 — Single Single Open Drain — PART Note: All devices are available in tape and reel in 2.5k increments. For tape and reel orders, add a “T” after the “+” to complete the part number. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX6782–MAX6790 General Description The MAX6782–MAX6790 are low-power, 1% accurate, dual-/triple-/quad-level battery monitors offered in small TDFN and TQFN packages. These devices are ideal for monitoring single lithium-ion (Li+) cells, or multicell alkaline/NiCd/NiMH power sources. These devices feature fixed and adjustable hysteresis options to eliminate output chattering associated with battery-voltage monitors. MAX6782–MAX6790 Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) BATT.........................................................................-0.3V to +6V IN1–IN4, LBH1, LBL1, LBH2, LBL2 ..................-0.3V to Min ((VBATT + 0.3V) and +6V) HADJ1–HADJ4, REF .......-0.3V to Min ((VBATT + 0.3V) and +6V) LBO1–LBO4 (push-pull) ..-0.3V to Min ((VBATT + 0.3V) and +6V) LBO1–LBO4 (open drain).........................................-0.3V to +6V Input Current (all pins) ........................................................20mA Output Current (all pins) .....................................................20mA Continuous Power Dissipation (TA = +70°C) 8-Pin TDFN (derate 23.8mW/°C above +70°C) ..........1905mW 10-Pin TDFN (derate 24.4mW/°C above +70°C) ........1951mW 12-Pin Thin QFN (derate 16.7mW/°C above +70°C) ..1333mW 16-Pin Thin QFN (derate 20.8mW/°C above +70°C) ..1667mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ………………………………………+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Soldering Temperature (reflow) .......................................+260°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 Startup Time (Note 3) CONDITIONS MIN TYP MAX TA = 0°C to +70°C 1.05 5.5 TA = -40°C to +85°C 1.2 5.5 VBATT = 3.7V, no load 6.3 VBATT = 1.8V, no load 5.7 VBATT rising from 0 to 1.6V UNITS V 10 µA 5 ms µA MAX6782/MAX6783/MAX6784/MAX6785 IN_ Falling Threshold (Note 4) VINF IN_ Rising Threshold (Note 4) VINR IN_, HADJ_ Input Leakage Current Reference Output 0.5994 0.6055 0.6115 5% hysteresis (B version) 0.5723 0.5781 0.5839 10% hysteresis (C version) 0.5422 0.5477 0.5531 0.6024 0.6085 0.6146 V 5 nA VIN_, VHADJ_ ≥ 0.3V VREF Reference Load Regulation Reference Temperature Coefficient 0.5% hysteresis (A version) 0.6024 IREF = 0 to 1mA TEMPCO Reference Short-Circuit Current Hysteresis Adjustment Range 0.6085 VHALL Hysteresis Adjustment Logic High VHALH 0.17 VTH 0.6024 V 0.3 mV/mA 15 ppm/°C 20 mA 0.4 Hysteresis Adjustment Logic Low 0.6146 V VREF V 0.05 V V MAX6786/MAX6787/MAX6788 LBL_, LBH_ Threshold LBL_, LBH_ Input Leakage Current 2 0.6085 VLBL, VLBH_ ≥ 0.3V _______________________________________________________________________________________ 0.6146 V 5 nA Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages MAX6782–MAX6790 ELECTRICAL CHARACTERISTICS (continued) (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 MAX6782–MAX6788 LBO_ Propagation Delay LBO_ Output Low Voltage (PushPull or Open Drain) LBO_ Output High Voltage (Push-Pull) (Note 5) tPD VOL VOH LBO_ Output Leakage Current (Open Drain) ±100mV overdrive 30 µs VBATT ≥ 1.2V, ISINK = 100µA 0.3 V VBATT ≥ 2.7V, ISINK = 1.2mA 0.3 V VBATT ≥ 4.5V, ISINK = 3.2mA 0.4 V VBATT ≥ 1.6V, ISOURCE = 10µA 0.8 x VBATT V VBATT ≥ 2.7V, ISOURCE = 500µA 0.8 x VBATT V VBATT ≥ 4.5V, ISOURCE = 800µA 0.8 x VBATT V Output not asserted, VLBO_ = 0 or 5V 500 nA MAX6789/MAX6790 IN_ Rising Threshold VTH+ 0.6024 IN_ Hysteresis 0.6085 0.6146 31 VIN_ ≥ 0.3V IN_ Input Leakage Current OV, OV Delay Time tPD OV Output Low Voltage (PushPull or Open Drain) OV Output High Voltage (PushPull) (Note 5) VOL VOH OV Output Leakage Current (Open Drain) OV Output Low Voltage (Push-Pull or Open Drain) VOL 5 ±100mV overdrive 30 0.3 VBATT ≥ 2.7V, ISINK = 1.2mA, output asserted 0.3 VBATT ≥ 4.5V, ISINK = 3.2mA, output asserted 0.4 0.8 x VBATT VBATT ≥ 2.7V, ISOURCE = 500µA, output not asserted 0.8 x VBATT VBATT ≥ 4.5V, ISINK = 800µA, output not asserted 0.8 x VBATT nA µs VBATT ≥ 1.6V, ISINK = 100µA, output asserted VBATT ≥ 1.2V, ISOURCE = 10µA, output not asserted V mV V V Output not asserted, VOV, VOV = 0 or 5V 500 VBATT ≥ 1.2V, ISINK = 100µA, output not asserted 0.3 VBATT ≥ 2.7V, ISINK = 1.2mA, output not asserted 0.3 VBATT ≥ 4.5V, ISINK = 3.2mA, output not asserted 0.4 nA V _______________________________________________________________________________________ 3 MAX6782–MAX6790 Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages ELECTRICAL CHARACTERISTICS (continued) (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 OV Output High Voltage (PushPull ) (Note 5) SYMBOL VOH OV Output Leakage Current (Open Drain) CONDITIONS MIN VBATT ≥ 1.6V, ISOURCE = 10µA, output asserted 0.8 x VBATT VBATT ≥ 2.7V, ISOURCE = 500µA, output asserted 0.8 x VBATT VBATT ≥ 4.5V, ISOURCE = 800µA, output asserted 0.8 x VBATT VIL CLEAR Input High Voltage VIH 25 CLEAR Minimum Pulse Width 1 UNITS 500 nA 0.3 x VBATT V 0.7 x VBATT CLEAR Pullup Resistance tCLD MAX V Output asserted, VOV = 0 or 5V CLEAR Input Low Voltage CLEAR Delay Time TYP V 80 kΩ µs 300 ns Note 1: Devices are tested at TA = +25°C and guaranteed by design for TA = TMIN to TMAX as specified. Note 2: Operating voltage range ensures low battery output is in the correct state. Minimum battery voltage for electrical specification is 1.6V. Note 3: Reference and threshold accuracy is only guaranteed after the startup time. Startup time is guaranteed by design. Note 4: The rising threshold is guaranteed to be higher than the falling threshold. Note 5: The source current is the total source current from all outputs. 4 _______________________________________________________________________________________ Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages PROPAGATION DELAY vs. TEMPERATURE 6.5 6.0 5.5 VBATT = 1.8V 50 40 30 20 4.5 10 4.0 0 -40 -15 10 35 60 85 MAX6782 toc03 1000 OUTPUT ASSERTED ABOVE THIS LINE 900 800 700 600 500 400 300 200 100 0 -40 -15 10 35 60 85 1 10 1000 100 TEMPERATURE (°C) TEMPERATURE (°C) THRESHOLD OVERDRIVE (mV) NORMALIZED THRESHOLD VOLTAGES vs. TEMPERATURE (MAX6782TEA) NORMALIZED THRESHOLD VOLTAGES vs. TEMPERATURE (MAX6782TEB) NORMALIZED THRESHOLD VOLTAGES vs. TEMPERATURE (MAX6782TEC) 1.003 FALLING 1.002 1.001 1.000 0.999 0.998 0.997 RISING 1.004 1.003 1.002 1.000 0.999 0.997 0.996 0.995 10 35 TEMPERATURE (°C) 60 85 FALLING 0.998 0.995 -15 RISING 1.001 0.996 -40 NORMALIZED AT TA = +25°C 1.005 MAX6782 toc06 1.004 1.005 NORMALIZED AT TA = +25°C 1.004 NORMALIZED THRESHOLD (V) NORMALIZED AT TA = +25°C MAX6782 toc05 MAX6782 toc04 1.005 NORMALIZED THRESHOLD (V) 60 PROPAGATION DELAY (µs) 7.0 5.0 VIN_ = ±100mV OVERDRIVE NORMALIZED THRESHOLD (V) SUPPLY CURRENT (µA) VBATT = 3.6V MAX6782 toc02 VBATT = 5V 7.5 70 MAX6782 toc01 8.0 MAXIMUM TRANSIENT DURATION vs. THRESHOLD OVERDRIVE MAXIMUM TRANSIENT DURATION (µs) SUPPLY CURRENT vs. TEMPERATURE 1.003 1.002 RISING 1.001 1.000 0.999 0.998 FALLING 0.997 0.996 0.995 -40 -15 10 35 TEMPERATURE (°C) 60 85 -40 -15 10 35 60 85 TEMPERATURE (°C) _______________________________________________________________________________________ 5 MAX6782–MAX6790 Typical Operating Characteristics (VBATT = 3.6V, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VBATT = 3.6V, TA = +25°C, unless otherwise noted.) 0.4 0.3 VBATT = 5.0V 0.2 5.0 VBATT = 5.0V 4.5 4.0 3.5 VBATT = 3.3V 3.0 2.5 VBATT = 1.8V 2.0 0.1 6 9 12 0.608 1 2 3 0.600 -40 5 4 -15 10 35 SOURCE CURRENT (mA) TEMPERATURE (°C) REFERENCE VOLTAGE vs. REFERENCE CURRENT REFERENCE VOLTAGE vs. SUPPLY VOLTAGE CLEAR LATCH CIRCUIT 0.62 0.61 0.60 0.59 0.58 0.6093 IN_ 5V/div 0.6092 0.6091 CLEAR 5V/div 0.6090 0.6089 0.6088 0.57 0.6087 0.56 0.6086 0.55 MAX6782TEB 0.6094 OV 5V/div 0.6085 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 REFERENCE CURRENT (mA) 85 MAX6782 toc12 0.6095 REFERENCE VOLTAGE (V) 0.63 0 60 SINK CURRENT (mA) MAX6782TEB 0.64 0 15 0.612 MAX6782 toc11 0.65 3 MAX6782 toc10 0 0.616 0.604 1.0 0 MAX6782TEA PUSH-PULL VERSIONS 1.5 6 MAX6782 toc08 VBATT = 3.3V 0.620 REFERENCE VOLTAGE (V) OUTPUT VOLTAGE (V) 0.5 5.5 OUTPUT VOLTAGE (V) VBATT = 1.8V MAX6782 toc07 0.6 REFERENCE VOLTAGE vs. TEMPERATURE LBO OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT MAX6782 toc09 LBO OUTPUT VOLTAGE LOW vs. SINK CURRENT VREF (V) MAX6782–MAX6790 Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 100µs/div SUPPLY VOLTAGE (V) _______________________________________________________________________________________ Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages MAX6782/MAX6783/MAX6784/MAX6785 PIN MAX6782/ MAX6783 MAX6784/ MAX6785 NAME 1 1 IN2 Battery Monitor Input 2. Connect to an external resistive divider to set the trip threshold for monitor 2. 2 2 IN3 Battery Monitor Input 3. Connect to an external resistive divider to set the trip threshold for monitor 3. 3 — IN4 Battery Monitor Input 4. Connect to an external resistive divider to set the trip threshold for monitor 4. 4 3 REF Reference Output. REF can source up to 1mA. REF does not require an external bypass capacitor for stability. Keep the capacitance from REF to GND below 50pF. HADJ1 Hysteresis Adjustment Input 1. Connect HADJ1 to GND to select an internal preset hysteresis option. Connect a resistive divider from REF to HADJ1 and to GND to externally adjust the hysteresis for IN1 from its internal preset hysteresis (see Figure 6). HADJ2 Hysteresis Adjustment Input 2. Connect HADJ2 to GND to select an internal preset hysteresis option. Connect a resistive divider from REF to HADJ2 and to GND to externally adjust the hysteresis for IN2 from its internal preset hysteresis (see Figure 6). HADJ3 Hysteresis Adjustment Input 3. Connect HADJ3 to GND to select an internal preset hysteresis option. Connect a resistive divider from REF to HADJ3 and to GND to externally adjust the hysteresis for IN3 from its internal preset hysteresis (see Figure 6). 5 6 7 4 5 6 FUNCTION 8 — HADJ4 Hysteresis Adjustment Input 4. Connect HADJ4 to GND to select an internal preset hysteresis option. Connect a resistive divider from REF to HADJ4 and to GND to externally adjust the hysteresis for IN4 from its internal preset hysteresis (see Figure 6). 9 — LBO4 Active-Low, Low-Battery Output 4. LBO4 asserts when VIN4 falls below the falling threshold voltage. LBO4 deasserts when VIN4 exceeds the rising threshold voltage. 10 7 LBO3 Active-Low, Low-Battery Output 3. LBO3 asserts when VIN3 falls below the falling threshold voltage. LBO3 deasserts when VIN3 exceeds the rising threshold voltage. 11 8 LBO2 Active-Low, Low-Battery Output 2. LBO2 asserts when VIN2 falls below the falling threshold voltage. LBO2 deasserts when VIN2 exceeds the rising threshold voltage. 12 9 LBO1 Active-Low, Low-Battery Output 1. LBO1 asserts when VIN1 falls below the falling threshold voltage. LBO1 deasserts when VIN1 exceeds the rising threshold voltage. 13 10 BATT Battery Input. Power supply to the device. For better noise immunity, bypass BATT to GND with a 0.1µF capacitor as close to the device as possible. 14 11 GND Ground 15 — N.C. No Connection. Not internally connected. 16 12 IN1 Battery Monitor Input 1. Connect to an external resistive divider to set the trip threshold for monitor 1. — — EP Exposed Pad. Connect EP to the ground plane. Do not use EP as the only ground connection. _______________________________________________________________________________________ 7 MAX6782–MAX6790 Pin Description MAX6782–MAX6790 Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages Pin Description (continued) MAX6786/MAX6787/MAX6788 PIN NAME 1 LBL1 FUNCTION 2 LBH1 Rising Trip Level Input 1. Connect to an external resistive divider to set the rising trip level. 3 LBL2 Falling Trip Level Input 2. Connect to an external resistive divider to set the falling trip level. 4 LBH2 Rising Trip Level Input 2. Connect to an external resistive divider to set the rising trip level. 5 GND Ground 6 LBO2 Active-Low, Low-Battery Output 2. LBO2 asserts when VLBL2 falls below the falling threshold voltage. LBO2 deasserts when VLBH2 exceeds the rising threshold voltage. 7 LBO1 Active-Low, Low-Battery Output 1. LBO1 asserts when VLBL1 falls below the falling threshold voltage. LBO1 deasserts when VLBH1 exceeds the rising threshold voltage. 8 BATT Battery Input. Power supply to the device. For better noise immunity, bypass BATT to GND with a 0.1µF capacitor as close to the device as possible. — EP Falling Trip Level Input 1. Connect to an external resistive divider to set the falling trip level. Exposed Pad. Connect EP to the ground plane. Do not use EP as the only ground connection. MAX6789/MAX6790 PIN NAME 1 IN1 Overvoltage Monitor Input 1 2 IN2 Overvoltage Monitor Input 2 3 IN3 Overvoltage Monitor Input 3 4 IN4 Overvoltage Monitor Input 4 5 GND 6 CLEAR 7 N.C. FUNCTION Ground Active-Low Clear Input. OV and OV do not latch when an overvoltage fault is detected if CLEAR is held low. CLEAR has an internal pullup resistor to BATT. No Connection. Not internally connected. 8 OV Active-Low Overvoltage Output. When any of the inputs (VIN_) exceeds its respective rising threshold voltage, OV asserts and stays asserted until CLEAR is pulled low or the power to the device is cycled. OV does not latch when an overvoltage fault is detected if CLEAR is held low. 9 OV Active-High Overvoltage Output. Inverse of OV. 10 BATT — EP Battery Input. Power supply to the device. For better noise immunity, bypass BATT to GND with a 0.1µF capacitor as close to the device as possible. Exposed Pad. Connect EP to the ground plane. Do not use EP as the only ground connection. Detailed Description The MAX6782–MAX6788 are designed to monitor two to four battery levels (1% accuracy) and assert an active-low output indicator when the monitored voltage level falls below the user-set threshold. Each battery level is associated with an independent open-drain or push-pull output. Each of these independent outputs can be used to provide low battery warnings at different voltage levels. Each of these monitored levels offers fixed or adjustable hysteresis in order to prevent the output from chattering as the battery recovers from the 8 lighter loads. The MAX6782–MAX6785 also feature reference outputs that can source up to 1mA. The MAX6789/MAX6790 monitor four overvoltage conditions and assert the complementary overvoltage outputs when any voltage at the inputs exceeds its respective threshold. The MAX6789/MAX6790 allow each trip threshold to be set with external resistors. These devices also feature a latch and a clear function. Figures 1, 2, and 3 show the simplified block diagrams for the MAX6782–MAX6790. See the Selector Guide. _______________________________________________________________________________________ Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages MAX6782–MAX6790 BATT REF IN1 COMPARATOR SECTION 1 REFERENCE HADJ1 LBO1 IN2 COMPARATOR SECTION 2 HADJ2 INTERNAL HYSTERESIS LADDER LBO2 IN3 COMPARATOR SECTION 3 HADJ3 LBO3 MAX6782 MAX6783 MAX6784 MAX6785 IN4 COMPARATOR SECTION 4 HYSTERESIS SELECT HADJ4 LBO4 GND ( ) MAX6782/MAX6783 ONLY Figure 1. MAX6782–MAX6785 Block Diagram BATT MAX6786 MAX6787 MAX6788 REF R1 LBO_ LBL_ RHYST LBH_ R2 GND Figure 2. MAX6786/MAX6787/MAX6788 Block Diagram _______________________________________________________________________________________ 9 MAX6782–MAX6790 Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages BATT IN_ MAX6789 MAX6790 REF OV LATCH CONTROL CLEAR GND Figure 3. MAX6789/MAX6790 Block Diagram Low-Battery/Overvoltage Output Hysteresis All devices are offered with either push-pull or opendrain outputs (see the Selector Guide). The MAX6788 has one push-pull output and one open-drain output, configured as shown in Table 1. Input hysteresis defines two thresholds, separated by 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. Figures 4 and 5 show 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. Table 1. MAX6788 Outputs DEVICE LBO1 LBO2 MAX6788 Push-Pull Open Drain All open-drain outputs require an external pullup resistor. The open-drain pullup resistor may be connected to an external voltage up to +6V, regardless of the voltage at BATT. 10 ______________________________________________________________________________________ Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages MAX6782–MAX6790 VINR INTERNAL HYSTERESIS VINF IN_ VHALL VHADJ_ tPD tPD LBO_ A) NORMAL OPERATION FOR VHADJ_ < VHALL. VINR VINF INTERNAL HYSTERESIS IN_ VHADJ_ VHALH tPD tPD LBO_ B) NORMAL OPERATION FOR VHADJ_ > VHALH. Figure 4. MAX6782–MAX6785 Timing ______________________________________________________________________________________ 11 MAX6782–MAX6790 Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages VTH+ VTHIN_ CLEAR OV tPD tCLD OV Figure 5. MAX6789/MAX6790 Timing MAX6782–MAX6785 Hysteresis Factory-Set Hysteresis The MAX6782–MAX6785 have factory-set hysteresis for ease of use and reduced external parts 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 factory-set hysteresis. For factory-set hysteresis, connect HADJ_ to GND. Table 2. Typical Falling and Rising Thresholds for MAX6782–MAX6785 (HADJ_ = GND) DEVICE OPTION PERCENT HYSTERESIS (%) FALLING THRESHOLD (VINF) (V) RISING THRESHOLD (VINR) (V) A 0.5 0.6055 0.6085 B 5 0.5781 0.6085 C 10 0.5477 0.6085 12 Externally Adjusted Hysteresis The MAX6782–MAX6785 can also be configured for externally adjustable hysteresis. Connect a resistive divider from REF to HADJ_ and to GND (Figure 6) to set the hysteresis voltage. The hysteresis adjustment range is from 0.4V to V REF , and the voltage at HADJ_ (V HADJ_ ) must be set higher than Hysteresis Adjustment Logic High (VHALH) (Figure 4b). Note that if VHADJ_ is lower than Hysteresis Adjustment Logic Low (VHALL), these devices switch back to the internal factory-set hysteresis (Figure 4a). MAX6786/MAX6787/MAX6788 Adjustable Hysteresis The MAX6786/MAX6787/MAX6788 offer external hysteresis control through the resistive divider that monitors battery voltage. Figure 2 shows the connections for external hysteresis. See Calculating an External Hysteresis Resistive Divider (MAX6786/MAX6787/MAX6788) section for more information. ______________________________________________________________________________________ Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages old (VINF) on the associated IN_ (the rising threshold (VINR) is fixed). See Table 2. Calculate R3 using: e × VREF R3 = A IL where eA is the fraction of the maximum acceptable absolute resistive divider error attributable to the input leakage current (use 0.01 for 1%), VREF is the reference output voltage, and IL is the worst-case HADJ_ leakage current. Calculate R4 using: Applications Information R4 = 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. See Figure 6 and calculate the optimum value for R1 using: e × VBATT R1 = A IL where eA is the fraction of the maximum acceptable absolute resistive divider error attributable to the input leakage current (use 0.01 for 1%), VBATT is the battery voltage at which LBO should activate, and IL is the worst-case IN_ leakage current, from the Electrical Characteristics. For example, for 0.5% error, a 2.8V battery minimum, and 5nA leakage, R 1 = 2.80MΩ. Calculate R2 using: R2 = VINF × R1 VBATT − VINF where VINF is the falling threshold voltage from Table 2. Continuing the above example, and selecting VINF = 0.5477V (10% hysteresis device), R2 = 681kΩ. There are other sources of error for the battery threshold, including resistor and input monitor tolerances. Calculating an External Hysteresis Resistive Divider (MAX6782–MAX6785) To set the hysteresis, place a resistive divider from REF to HADJ_ as shown in Figure 6. The resistive divider sets voltage on HADJ_, which controls the falling thresh- VINF × R3 VREF − VINF where VINF is the desired falling voltage threshold. To calculate the percent hysteresis, use: −V V Hysteresis (%) = 100 × INR INF VINR where VINR is the rising voltage. Calculating an External Hysteresis Resistive Divider (MAX6786/MAX6787/MAX6788) Setting the hysteresis externally requires calculating three resistor values, as indicated in Figure 2. First calculate R1 using: e × VBATT R1 = A IL and R20 using: R20 = VTH × R1 (as in the above example) VBATT − VTH where R20 = R2 + RHYST determine the total resistivedivider current, ITOTAL, at the trip voltage using: ITOTAL = VBATT R1 + R20 Then, determine RHYST using: V RHYST = HYST ITOTAL where VHYST is the required hysteresis voltage. Finally, determine R2 using: R2 = R20 - RHYST ______________________________________________________________________________________ 13 MAX6782–MAX6790 Reference Output The reference output can provide up to 1mA of output current. The output is not buffered. Excessive loading affects the accuracy of the thresholds. An external capacitor is not required for stability and is stable for capacitive loads up to 50pF. In applications where the load or the supply can experience step changes, a capacitor reduces the amount of overshoot (undershoot) and improves the circuit’s transient response. Place the capacitor as close to the device as possible for best performance. MAX6782–MAX6790 Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages Monitoring a Battery Voltage Higher than the Allowable VBATT Adding External Capacitance to Reduce Noise and Transients For monitoring higher voltages, supply a voltage to BATT, which 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. 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. Maintaining Reference Accuracy Reverse-Battery Protection Since the ground connection of the MAX6782–MAX6790 has a small series resistance, any current flowing into an output flows to ground and causes a small voltage to develop from the internal ground to GND. This has the effect of slightly increasing the reference voltage. To minimize the effect on the reference voltage, keep the total output sink current below 3mA. To prevent damage to the device during a reverse-battery condition, connect the MAX6782–MAX6785 in the configuration shown in Figure 6a or 6b. For the internal reversebattery protection to function correctly on the MAX6782– MAX6790, several conditions must be satisfied: • The connections to IN_/LBL_/LBH_ must be made to the center node of a resistive divider going from BATT to GND. The Thevenin equivalent impedance of the resistive divider must not fall below 1kΩ in order to limit the current. • HADJ_ (MAX6782–MAX6785 only) must either be connected to GND or to the center node of a resistive divider going from REF to GND. BATT R1 LBO_ IN_ R2 REF • The outputs may only be connected to devices powered by the same battery as the MAX6782– MAX6790. MAX6782 MAX6783 MAX6784 MAX6785 Note that the MAX6782–MAX6790 will not protect other devices in the circuit. HADJ_ Additional Application Circuit GND Figure 7 shows the MAX6786/MAX6787/MAX6788 in a typical two-battery-level monitoring circuit. A) FACTORY PRESET HYSTERESIS CONNECTION BATT LBL1 1 BATT R1 IN_ R2 REF R3 LBO1 LBO_ MAX6782 MAX6783 MAX6784 MAX6785 LBH1 MAX6786 MAX6787 MAX6788 LBL2 HADJ_ R4 LBO2 LBH2 GND GND B) EXTERNAL HYSTERESIS ADJUST CONNECTION Figure 6. Internal Preset or Externally Adjusted Hysteresis Connection 14 Figure 7. Two-Battery-Level Monitor Configuration ______________________________________________________________________________________ Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages BATT IN1 LBO1 DEAD BATTERY IN2 LBO2 BACKUP MEMORY IN3 LBO3 SHUT DOWN SUBSYSTEM IN4 LBO4 SLOW DOWN PROCESSOR SPEED MAX6782 MAX6783 REF HADJ_ Top Marks PART MAX6782TEA+ TOP MARK +AEG MAX6782TEB+ +AEH MAX6782TEC+ +AEI MAX6783TEA+ +AEJ GND Ordering Information (continued) PART TEMP RANGE PIN-PACKAGE MAX6786TA+T -40°C to +85°C 8 TDFN-EP* MAX6787TA+T -40°C to +85°C 8 TDFN-EP* MAX6788TA+T -40°C to +85°C 8 TDFN-EP* MAX6789TB+T -40°C to +85°C 10 TDFN-EP* -40°C to +85°C 10 TDFN-EP* MAX6783TEB+ +AEK MAX6790TB+T MAX6783TEC+ +AEL +Denotes a lead-free/RoHS-compliant package. *EP = Exposed pad. The MAX6782/MAX6783/MAX6784/MAX6785 are available with factory-trimmed hysteresis. Specify trim by replacing “_” with “A” for 0.5%, “B” for 5%, or “C” for 10% hysteresis. MAX6784TCA+ +AAV MAX6784TCB+ +AAW MAX6784TCC+ +AAX MAX6785TCA+ +AAY MAX6785TCB+ +AAZ MAX6785TCC+ +ABA MAX6786TA+ +APU MAX6787TA+ +APV MAX6788TA+ +APW MAX6789TB+ +AQI MAX6790TB+ +AQJ ______________________________________________________________________________________ 15 MAX6782–MAX6790 Typical Operating Circuit Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages LBO2 LBO3 LBO4 LBO1 LBO2 LBO3 12 11 10 9 9 8 7 HADJ4 GND 14 7 HADJ3 6 HADJ2 5 HADJ1 EP 2 3 4 1 IN2 2 BATT LBO1 LBO2 GND BATT OV OV N.C. CLEAR 7 6 5 10 9 8 7 6 HADJ2 MAX6789 MAX6790 3 4 1 2 LBH2 IN1 IN2 3 4 5 GND 2 IN4 1 LBL2 EP LBH1 + LBL1 EP TDFN TDFN Package Information Chip Information For the latest package outline information and land patterns, go to www.maxim-ic.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 16 5 3 8 MAX6786 MAX6787 MAX6788 PROCESS: BiCMOS HADJ3 THIN QFN THIN QFN + 6 HADJ1 EP + REF IN2 1 IN1 12 IN4 + MAX6784 MAX6785 IN3 IN1 16 GND 11 MAX6782 MAX6783 N.C. 15 BATT 10 REF 8 IN3 BATT 13 IN3 TOP VIEW LBO1 MAX6782–MAX6790 Pin Configurations PACKAGE CODE DOCUMENT NO. 8 TDFN-EP T833-3 21-0137 10 TDFN-EP T1033-1 21-0137 12 TQFN-EP T1233-1 21-0136 16 TQFN-EP T1633-4 21-0136 ______________________________________________________________________________________ Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 0 8/06 Initial release 1 10/06 Released the MAX6784, MAX6786–MAX6790. 1, 15 — 2 5/08 Updated the Pin Description tables. 7, 8 3 3/10 Updated the Absolute Maximum Ratings and the Electrical Characteristics table. 2 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 17 © 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX6782–MAX6790 Revision History