19-1157; Rev 3; 3/10 Micropower, Latching Voltage Monitors in SOT23-5 The MAX834/MAX835 micropower voltage monitors contain a 1.204V precision bandgap reference, comparator, and latched output in a 5-pin SOT23 package. Using the latched output prevents deep discharge of batteries. The MAX834 has an open-drain, n-channel output driver, while the MAX835 has a push-pull output driver. Two external resistors set the trip-threshold voltage. The MAX834/MAX835 feature a level-sensitive latch, eliminating the need to add hysteresis to prevent oscillations in battery-load-disconnect applications. Features ♦ Prevent Deep Discharge of Batteries ♦ Precision ±1.25% Voltage Threshold ♦ Latched Output (Once Low, Stays Low Until Cleared) ♦ SOT23-5 Package ♦ Low Cost ♦ +2.5V to +11V Wide Operating Voltage Range ♦ < 2µA Typical Supply Current ♦ Open-Drain Output (MAX834)/Push-Pull Output (MAX835) Ordering Information Applications Precision Battery Monitors PART Load Switching PIN-PACKAGE Battery-Powered Systems Pin Configuration Typical Operating Circuit VCC RL OUT CLEAR (MAX834 ONLY) TOP VIEW CLEAR 1 OUT GND 2 MAX834 MAX835 GND VCC 5 OUT 4 IN MAX834 MAX835 VCC 3 SOT23-5 IN VCC AAAX 5 SOT23 AAAY MAX835EUK-T Note: All devices are specified over the -40°C to +85°C operating temperature range. Devices are available in both leaded and lead-free packaging. Specify lead-free by changing “-T” with “+T” when ordering. Threshold Detectors CLEAR LATCH TOP MARK 5 SOT23 MAX834EUK-T R1 0.1μF R2 ________________________________________________________________ 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 MAX834/MAX835 General Description MAX834/MAX835 Micropower, Latching Voltage Monitors in SOT23-5 ABSOLUTE MAXIMUM RATINGS VCC, OUT (MAX834), CLEAR to GND ....................-0.3V to +12V IN, OUT (MAX835) to GND.........................-0.3V to (VCC + 0.3V) INPUT Current VCC ................................................................................20mA IN....................................................................................10mA OUT Current.......................................................................-20mA VCC Rate of Rise .............................................................100V/µs Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/C above +70°C) .............571mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Soldering Temperature (reflow) .......................................+240°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 (VCC = +2.5V to +11V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Operating Voltage Range (Note 1) Supply Current (Note 2) SYMBOL CONDITIONS Threshold Voltage VTH Threshold Voltage Hysteresis VHYST IN Operating Voltage Range (Note 1) VIN IN Leakage Current (Note 3) IIN Propagation Delay tPL Glitch Immunity TYP 2.5 VCC ICC MIN TA = +25°C VIN = 1.6V, OUT = VCC = 3.6V low, VCLEAR ≥ TA = TMIN to TMAX VCC - 0.25V or VCLEAR ≤ 0.25V VCC = full operating range 2.4 VIN = 1.25V, OUT = high, VCLEAR ≥ VCC - 0.25V or VCLEAR ≤ 0.25V 1.1 VIN falling MAX UNITS 11.0 V 5 10 15 TA = +25°C µA 4 VCC = 3.6V TA = TMIN to TMAX 8 VCC = full operating range 13 TA = +25°C 1.185 1.204 1.215 TA = 0°C to +70°C 1.169 1.204 1.231 VCC = 5V, IN = low to high 6 0 VIN = VTH ±3 V mV VCC - 1 V ±12 nA VCC = 5V, 50mV overdrive 80 VCC = 5V, 100mV overdrive 35 µs µs OUT Rise Time tRT VCC = 5V, no load (MAX835 only) 200 ns OUT Fall Time tFT VCC = 5V, no load (MAX834 pullup = 10kΩ) 480 ns Output Leakage Current (Note 4) ILOUT VIN > VTH(MAX) (MAX834 only) Output-Voltage High VOH VIN > VTH(MAX), ISOURCE = 500µA (MAX835 only) Output-Voltage Low VOL VIN < VTH(MIN), ISINK = 500µA CLEAR Input High Voltage VCIH 2 ±1 VCC 0.5 V 0.4 2 _______________________________________________________________________________________ µA V V Micropower, Latching Voltage Monitors in SOT23-5 MAX834/MAX835 ELECTRICAL CHARACTERISTICS (continued) (VCC = +2.5V to +11V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CLEAR Input Low Voltage CONDITIONS MIN TYP VCIL CLEAR Input Leakage Current tCLEAR CLEAR Input Pulse Width ±1 tCLR MAX UNITS 0.4 V ±100 nA 1 µs Note 1: The voltage-detector output remains in the correct state for VCC down to 1.2V when VIN ≤ VCC/2. Note 2: Supply current has a monotonic dependence on VCC (see the Typical Operating Characteristics). Note 3: IN leakage current has a monotonic dependence on VCC (see the Typical Operating Characteristics). Note 4: The MAX834 open-drain output can be pulled up to a voltage greater than VCC, but may not exceed 11V. __________________________________________Typical Operating Characteristics (VCC = +5V, Typical Operating Circuit, TA = +25°C, unless otherwise noted.) 3.5 3.0 2.5 2.0 60 50 40 40 60 80 TA = -40°C 100 MAXMAX834/835-10 VIN = 1.25V 4.0 3.5 TA = +85°C 3.0 2.5 TA = +25°C 2.0 TA = -40°C 1.5 1.0 0.5 TA = +85°C 0 0 1 2 3 4 5 6 7 8 9 10 11 12 0 1 2 4 5 3 6 7 9 10 11 12 8 TEMPERATURE (°C) VIN (V) VCC (V) SUPPLY CURRENT vs. INPUT VOLTAGE SUPPLY CURRENT vs. INPUT VOLTAGE PROGRAMMED TRIP VOLTAGE vs. TEMPERATURE 3 2 1 9 8 7 6 5 4 3 0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 VIN (V) 5.6 5.2 4.8 4.0 3.6 3.2 1 2.4 0 2.0 0 1 2 3 4 5 6 7 VIN (V) 8 9 10 11 12 VTRIP ≈ 4.5V (FIGURE 2, R1 = 270kΩ, R2 = 100kΩ) 4.4 2.8 2 MAXMAX834/835-13 10 6.0 TRIP VOLTAGE (V) 4 VCC = 11.0V 11 SUPPLY CURRENT (μA) 5 12 MAXMAX834/835-12 VCC = 3.6V 0 4.5 20 0 20 TA = +25°C 30 10 0 MAXMAX834/835-08 70 1.0 6 SUPPLY CURRENT (μA) 80 1.5 -60 -40 -20 VCC = 11.0V SUPPLY CURRENT (μA) 4.0 90 INPUT LEAKAGE CURRENT (nA) VCC = 5.0V VIN = 1.2V MAX834/835-11 INPUT LEAKAGE CURRENT (nA) 5.0 4.5 SUPPLY CURRENT vs. SUPPLY VOLTAGE INPUT LEAKAGE CURRENT vs. INPUT VOLTAGE MAXMAX834/835-07 INPUT LEAKAGE CURRENT vs. TEMPERATURE VTRIP ≈ 3.3V (FIGURE 2, R1 = 180kΩ, R2 = 100kΩ) -60 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) _______________________________________________________________________________________ 3 _____________________________Typical Operating Characteristics (continued) (VCC = +5V, Typical Operating Circuit, TA = +25°C, unless otherwise noted.) MAX835 OUTPUT HIGH VOLTAGE vs. SUPPLY VOLTAGE 150 100 400 VCC - VOH (mV) TA = +25°C 300 250 200 TA = +25°C 150 50 100 0 VIN = 1.1V 15 TA = -40°C 1 2 4 5 3 6 7 9 10 11 12 8 TA = +25°C 10 TA = +85°C 5 0 0 0 0 1 2 3 4 5 6 9 10 11 12 7 8 0 1 2 3 4 5 6 7 8 9 10 11 12 VCC (V) VCC (V) VCC (V) MAX835 OUTPUT SHORT-CIRCUIT SOURCE CURRENT vs. SUPPLY VOLTAGE SUPPLY VOLTAGE FALLING TO OUT PROPAGATION DELAY vs. TEMPERATURE MAX835 OUTPUT RISE TIME vs. SUPPLY VOLTAGE TA = +25°C 10 5 TA = +85°C 1 2 3 4 5 6 110 100 90 80 600 500 TA = +25°C 400 10mV/μs 200 50 100 40 0 -60 -40 -20 0 20 40 60 80 100 TA = -40°C 0 1 2 3 4 5 6 7 8 9 10 11 12 TEMPERATURE (°C) VCC (V) OUTPUT FALL TIME vs. SUPPLY VOLTAGE OUTPUT LOW VOLTAGE vs. OUTPUT SINK CURRENT MAX835 OUTPUT HIGH VOLTAGE vs. OUTPUT SOURCE CURRENT 100k MAXMAX834/835-21 2.0 VCC = 11V 10k TA = +25°C VOL (mV) TA = +85°C 1.5 1.0 1k TA = +85°C 100 TA = +25°C 10 0.5 TA = -40°C 3 TA = -40°C 4 5 6 7 VCC (V) 8 9 10 11 12 100k VCC = 11V TA = +25°C 10k TA = +85°C 1k TA = -40°C 100 10 1 0 1 2 TA = +85°C 700 VCC (V) 2.5 0 800 300 70 9 10 11 12 7 8 900 1mV/μs 120 MAXMAX834/835-20 130 60 0 0 140 VCC - VOH (mV) 15 150 MAXMAX834/835-25 TA = -40°C 1000 MAXMAX834/835-19 20 160 RISE TIME (ns) VIN = 1.3V PROPAGATION DELAY (μs) MAXMAX834/835-18 25 4 20 TA = -40°C 50 TA = -40°C SHORT-CIRCUIT CURRENT (mA) TA = +85°C 350 MAXMAX834/835-23 VOL (mV) TA = +85°C ISOURCE = 500μA 450 MAXMAX834/835-17 200 500 MAXMAX834/835-15 ISINK = 500μA MAXMAX834/835-14 250 OUTPUT SHORT-CIRCUIT SINK CURRENT vs. SUPPLY VOLTAGE SHORT-CIRCUIT CURRENT (mA) OUTPUT LOW VOLTAGE vs. SUPPLY VOLTAGE FALL TIME (μs) MAX834/MAX835 Micropower, Latching Voltage Monitors in SOT23-5 1 0.1 1 10 OUTPUT SINK CURRENT (mA) 100 0.1 1 10 OUTPUT SOURCE CURRENT (mA) _______________________________________________________________________________________ 100 Micropower, Latching Voltage Monitors in SOT23-5 MAX835 OUTPUT HIGH VOLTAGE vs. OUTPUT SOURCE CURRENT TA = -40°C TA = +25°C 10 100 TA = -40°C TA = +25°C 10 1.5 MAXMAX834/835-30 TA = +85°C 1k VCC - VOH (mV) VOL (mV) VCC = 3.6V TA = +85°C 100 MAXMAX834/835-29 VCC = 3.6V 1k 10k MAXMAX834/835-27 10k CLEAR TO OUT PROPAGATION DELAY vs. TEMPERATURE VIN > VTH 1.3 PROPAGATION DELAY (μs) OUTPUT LOW VOLTAGE vs. OUTPUT SINK CURRENT VCC = 3.6V 1.1 0.9 VCC = 5.0V 0.7 0.5 VCC = 11.0V 0.3 1 1 0.1 1 10 OUTPUT SINK CURRENT (mA) 100 0.1 0.1 1 OUTPUT SOURCE CURRENT (mA) -60 -40 -20 10 0 20 40 60 80 100 TEMPERATURE (°C) ______________________________________________________________Pin Description PIN NAME FUNCTION Clear Input Resets the Latched Output. With VIN > VTH, pulse CLEAR high for a minimum of 1µs to reset the output latch. Connect to VCC to make the latch transparent. 1 CLEAR 2 GND System Ground 3 VCC System Supply Input 4 IN 5 OUT Noninverting Input to the Comparator. The inverting input connects to the internal 1.204V bandgap reference. Open-Drain (MAX834) or Push-Pull (MAX835) Latched Output. OUT is active-low. VCC CLEAR RL (MAX834 ONLY) CLEAR LATCH GND MAX834 MAX835 LATCH CLEAR GND OUT OUT IN VCC VCC MAX834 MAX835 IN 1.204V OUT VCC 0.1μF VTRIP = (1.204) R1 ( R1R2+ R2 ) R2 (UNITS ARE OHMS AND VOLTS) Figure 1. Functional Diagram Figure 2. Programming the Trip Voltage (VTRIP) _______________________________________________________________________________________ 5 MAX834/MAX835 _____________________________Typical Operating Characteristics (continued) (VCC = +5V, Typical Operating Circuit, TA = +25°C, unless otherwise noted.) MAX834/MAX835 Micropower, Latching Voltage Monitors in SOT23-5 _______________Detailed Description The MAX834/MAX835 micropower voltage monitors contain a 1.204V precision bandgap reference and a comparator with an output latch (Figure 1). The difference between the two parts is the structure of the comparator output driver. The MAX834 has an open-drain, n-channel output driver that can be pulled up to a voltage higher than VCC, but less than 11V. The MAX835’s output is push-pull and can both source and sink current. Programming the Trip Voltage (VTRIP) Two external resistors set the trip voltage, VTRIP (Figure 2). VTRIP is the point at which the falling monitored voltage (typically VCC) causes OUT to go low. IN’s high input impedance allows the use of large-value resistors without compromising trip voltage accuracy. To minimize current consumption, choose a value for R2 between 500kΩ and 1MΩ, then calculate R1 as follows: where VTRIP is the desired trip voltage and VTH is the threshold voltage (1.204V). The voltage at IN must be at least 1V less than VCC. Latched-Output Operation The MAX834/MAX835 feature a level-sensitive latch input (CLEAR), designed to eliminate the need for hysteresis in battery undervoltage-detection applications. When the monitored voltage (VMON) is above the programmed trip voltage (VTRIP) (as when the system battery is recharged or a fresh battery is installed), pulse CLEAR low-high-low for at least 1µs to reset the output latch (OUT goes high). When VMON falls below VTRIP, OUT goes low and remains low (even if VMON rises above VTRIP), until CLEAR is pulsed high again with VMON > VTRIP. Figure 3 shows the timing relationship between VMON, OUT, and CLEAR. R1 = R2 [(VTRIP / VTH) - 1] > VTRIP VMON < VTRIP > 1μs > 1μs > 1μs VCC CLEAR 0V VCC OUT 0V Figure 3a. Timing Diagram > VTRIP VMON < VTRIP VCC OUT 0V Figure 3b. Timing Diagram, CLEAR = VCC 6 _______________________________________________________________________________________ Micropower, Latching Voltage Monitors in SOT23-5 CLEAR LATCH VMON RL* R1 OUT CLEAR IN GND VCC OUT Load-Disconnect Switch VCC R2 MAX834 MAX835 0.1μF R1 + R2 R2 (UNITS ARE OHMS AND VOLTS) VTRIP = (1.204) *MAX834 ONLY Figure 4. Monitoring Voltages Other than VCC The circuit in Figure 5 is designed to prevent a leadacid battery or a secondary battery such as an NiCd, from sustaining damage through deep discharge. As the battery reaches critical undervoltage, OUT switches low. Q1 and Q2 turn off, disconnecting the battery from the load. The MAX835’s latched output prevents Q1 and Q2 from turning on again as the battery voltage relaxes to its open-circuit voltage when the load disconnects. CLEAR can be connected to a pushbutton switch, an RC network, or a logic gate to reset the latch when the battery is recharged or replaced. P Q1 CLEAR LATCH VBATT 1MΩ RLOAD R1 Q2 CLEAR N OUT GND VCC IN R2 MAX835 VCC 0.1μF Figure 5. Load-Disconnect Switch _______________________________________________________________________________________ 7 MAX834/MAX835 VCC Monitoring Voltages Other than VCC The Typical Operating Circuit for the MAX834/MAX835 monitors VCC. Voltages other than VCC can easily be monitored, as shown in Figure 4. Calculate VTRIP as in the Programming the Trip Voltage (V TRIP ) section. When monitoring voltages other than VCC, ensure that the maximum value for VMON is not exceeded: VMON(MAX) = (VCC - 1) (R1 + R2) / R2 ___________________Chip Information Package 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. TRANSISTOR COUNT: 74 PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 5 SOT23 U5-1 21-0057 __________________________________________________Tape-and-Reel Information E D P0 B0 t D1 F P NOTE: DIMENSIONS ARE IN MM. AND FOLLOW EIA481-1 STANDARD. 8 W P2 K0 A0 3.988 ±0.102 40.005 ±0.203 2.007 ±0.051 t 0.254 ±0.127 W 8.001 +0.305 -0.102 A0 3.200 ±0.102 E 1.753 ±0.102 B0 3.099 ±0.102 F 3.505 ±0.051 P010 D 1.499 +0.102 +0.000 K0 1.397 ±0.102 P2 3.988 ±0.102 0.991 +0.254 +0.000 P D1 P0 _______________________________________________________________________________________ 5 SOT23-5 MAX834/MAX835 Micropower, Latching Voltage Monitors in SOT23-5 Micropower, Latching Voltage Monitors in SOT23-5 REVISION NUMBER REVISION DATE 0 12/96 Initial release — 1 12/05 Added lead-free option to Ordering Information. 1 2 1/07 Fix limits in Electrical Characteristics and add lead-free part numbers. 3 3/10 Updated Electrical Characteristics. DESCRIPTION PAGES CHANGED 1, 2 3 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. 9 ___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX834/MAX835 Revision History