19-1695; Rev 1; 7/01 Quad Voltage Monitor in µMAX Package The MAX6338 quad voltage monitor is capable of monitoring up to four supplies without any external components. A variety of factory-trimmed threshold voltages and supply tolerances are available to optimize the MAX6338 for specific applications. The selection includes input options for monitoring +5.0V, +3.3V, +3.0V, +2.5V, +1.8V, and -5.0V voltages. An additional high-input impedance comparator option can be used as an adjustable voltage monitor, general-purpose comparator, or digital level translator. Each of the monitored voltages is available with trip thresholds to support power-supply tolerances of either 5% or 10% below the nominal voltage. An internal bandgap reference ensures accurate trip thresholds across the extended (-40°C to +85°C) operating temperature range. The MAX6338 consumes 25µA (typ) supply current and operates with supply voltages from +2.5V to +5.5V. An internal undervoltage lockout circuit forces all four digital outputs low when VCC drops below the minimum operating voltage. The four digital outputs all have weak internal pull-ups to VCC, allowing wire-ORed connection. Each input threshold voltage has an independent output. Features ♦ Monitors Four Voltages (Factory Programmed or User Adjustable) +5.0V, +3.3V, +3.0V, +2.5V, +1.8V, -5.0V (nominal) or User-Adjustable Settings ♦ Low 25µA Supply Current ♦ Four Independent, Open-Drain, Active-Low Outputs ♦ +2.5V to +5.5V Supply Voltage Range ♦ Guaranteed from -40°C to +85°C ♦ No External Components Required ♦ Small 10-Pin µMAX Package Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX6338_UB* -40°C to +85°C 10 µMAX *Insert the desired letter from the Selector Guide into the blank to complete the part number. Selector Guide NOMINAL INPUT VOLTAGE The MAX6338 is available in a 10-pin µMAX package. ________________________Applications PART IN1 (V) IN2 (V) IN3 (V) IN4 (V) SUPPLY TOLERANCE (%) MAX6338AUB 5 3.3 2.5 Adj* 10 Telecommunications High-End Printers Desktop and Notebook Computers Data Storage Equipment MAX6338BUB 5 3.3 2.5† Adj* 5 MAX6338CUB 5 3.3 1.8 Adj* 10 1.8† Adj* 5 10 MAX6338DUB 5 3.3 Networking Equipment MAX6338EUB 5 3.0 2.5 Adj* Industrial Equipment MAX6338FUB 5 3.0 2.5† Adj* 5 Set-Top Boxes MAX6338GUB 5 3.0 1.8 Adj* 10 MAX6338HUB 5 3.0 1.8† Adj* 5 10 Pin Configuration MAX6338IUB 5 3.3 2.5 1.8 MAX6338JUB 5 3.3 2.5† 1.8† 5 MAX6338KUB Adj* 3.3 2.5 Adj* 10 10 VCC MAX6338LUB Adj* 3.3 2.5† Adj* 5 9 OUT1 MAX6338MUB 5 3.0 Adj* -5 10 8 OUT2 MAX6338NUB 5 3.0 Adj* -5 5 7 OUT3 MAX6338OUB 5 3.3 Adj* -5 10 OUT4 MAX6338PUB 5 3.3 Adj* -5 5 TOP VIEW IN1 1 IN2 2 IN3 3 IN4 4 GND MAX6338 5 6 µMAX *Adjustable voltage based on +1.23V internal threshold. External threshold voltage can be set using an external resistor-divider. † Nominal input voltages for 1.8V and 2.5V are specified for 10% tolerances ________________________________________________________________ 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 MAX6338 General Description MAX6338 Quad Voltage Monitor in µMAX Package ABSOLUTE MAXIMUM RATINGS Terminal Voltage (with respect to GND) VCC ......................................................................-0.3V to +6V Output Voltages (OUT_) ...........................................-0.3V to +6V Input Voltages (IN_) (except -5V).............................-0.3V to +6V Input Voltage (-5V input) ..........................................-6V to +0.3V Continuous OUT_ Current...................................................20mA Continuous Power Dissipation (TA = +70°C) 10-pin µMAX (derate 5.6mW/°C above +70°C) ..........444mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Junction Temperature ......................................................+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 (VCC = +2.5V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C and VCC = +5V, unless otherwise noted.) (Note 1) PARAMETER Supply Voltage Range Supply Current Input Current (Note 2) SYMBOL CONDITIONS VCC ICC IIN_ MIN TYP +2.5 MAX UNITS +5.5 V VCC = +3V 25 50 VCC = +5V 35 65 VIN_ = input threshold voltage (+1.8V, +2.5V, +3.0V, +3.3V, +5.0V) 25 40 VIN_ = 0 to VCC (input threshold voltage =1.23V) -0.1 VIN_ = -5V (input threshold voltage = -5V) +0.1 -10 µA µA -20 +5.0V (-5%) Threshold VTH VIN decreasing 4.5 4.63 4.75 V +5.0V (-10%) Threshold VTH VIN decreasing 4.25 4.38 4.50 V +3.3V (-5%) Threshold VTH VIN decreasing 3.0 3.08 3.15 V +3.3V (-10%) Threshold VTH VIN decreasing 2.85 2.93 3.00 V +3.0V (-5%) Threshold VTH VIN decreasing 2.7 2.78 2.85 V +3.0V (-10%) Threshold VTH VIN decreasing 2.55 2.63 2.70 V +2.5V (-10%) Threshold VTH VIN decreasing 2.13 2.19 2.25 V +1.8V (-10%) Threshold VTH VIN decreasing 1.53 1.58 1.62 V -5.0V (+5%) Threshold VTH VIN increasing -4.75 -4.63 -4.50 V -5.0V (+10%) Threshold VTH VIN increasing -4.5 -4.38 -4.25 V Adjustable Threshold VTH VIN decreasing 1.20 1.23 1.26 V Threshold Voltage Temperature Coefficient Threshold Hysteresis VTHYST Propagation Delay tpd Output Low Voltage VOL Output High Voltage VOH VIN_ = VTH to (VTH - 50mV) or VTH to (VTH - 50mV) 60 ppm/°C 0.3 % 20 µs VCC = 5V, ISINK = 2mA 0.4 VCC = 2.5V, ISINK = 1.2mA 0.4 VCC = 1V, ISINK = 50µA VCC > 2.5V, ISOURCE = 6µA (minimum) 0.4 0.8 x VCC Note 1: 100% production tested at +25°C. Overtemperature limits guaranteed by design. Note 2: Guaranteed by design. 2 V _______________________________________________________________________________________ V Quad Voltage Monitor in µMAX Package NORMALIZED THRESHOLD ERROR vs. SUPPLY VOLTAGE 30 25 TA = -40°C 20 15 0.06 0.04 0.02 0 -0.02 3.0 3.5 4.0 4.5 5.0 0 -0.1 -0.2 -0.3 2.5 5.5 3.0 3.5 4.0 4.5 5.0 5.5 -40 -20 0 20 40 60 SUPPLY VOLTAGE (V) TEMPERATURE (°C) OUTPUT VOLTAGE LOW vs. SINK CURRENT PROPAGATION DELAY (WITH 100mV OVERDRIVE) PROPAGATION DELAY (WITH 20mV OVERDRIVE) VCC = 5V 0.5 0.4 MAX6338-05 0.6 80 MAX6338-06 SUPPLY VOLTAGE (V) MAX6338-04 2.5 VCC = +5V NORMALIZED TO +5V -0.04 -0.06 10 OUTPUT VOLTAGE LOW (V) 0.08 NORMALIZED THRESHOLD (%) 35 0.1 MAX6338-02 TA = +25°C TA = +85°C 0.10 NORMALIZED THRESHOLD ERROR (%) SUPPLY CURRENT (µA) 40 MAX6338-01 45 NORMALIZE THRESHOLD vs. TEMPERATURE MAX6338-03 SUPPLY CURRENT vs. SUPPLY VOLTAGE IN_ 50mV/div IN_ 20mV/div OUT_ 2V/div OUT_ 2V/div TA = +25°C 0.3 TA = +85°C 0.2 TA = -40°C 0.1 0 0 1 2 3 4 5 6 7 8 9 10 10µs/div 10µs/div SINK CURRENT (mA) _______________________________________________________________________________________ 3 MAX6338 Typical Operating Characteristics (VCC = +5V, TA = +25°C, unless otherwise noted.) Quad Voltage Monitor in µMAX Package MAX6338 Pin Description PIN NAME FUNCTION 1 IN1 Input Voltage 1. See Selector Guide for monitored voltages. 2 IN2 Input Voltage 2. See Selector Guide for monitored voltages. 3 IN3 Input Voltage 3. See Selector Guide for monitored voltages. 4 IN4 Input Voltage 4. See Selector Guide for monitored voltages. 5 GND Ground 6 OUT4 Output 4. OUT4 goes low when VIN4 falls below its absolute threshold. OUT4 is open drain with a 10µA internal pullup to VCC. 7 OUT3 Output 3. OUT3 goes low when VIN3 falls below its absolute threshold. OUT3 is open drain with a 10µA internal pullup to VCC. 8 OUT2 Output 2. OUT2 goes low when VIN2 falls below its absolute threshold. OUT2 is open drain with a 10µA internal pullup to VCC. 9 OUT1 Output 1. OUT1 goes low when VIN1 falls below its absolute threshold. OUT1 is open drain with a 10µA internal pullup to VCC. 10 VCC Power Supply. Connect VCC to a +2.5V to +5.5V supply. An undervoltage lockout circuit forces all OUT_ pins low when VCC drops below 2.5V. _______________Detailed Description The MAX6338 is a low-power (25µA), quad voltage monitor designed for multivoltage systems. Preset voltage options for +5.0V, +3.3V, +3.0V, +2.5V, +1.8V, and -5.0V make these quad monitors ideal for applications such as telecommunications, desktop and notebook computers, high-end printers, data storage equipment, and networking equipment. The MAX6338 has an internally trimmed threshold that minimizes or eliminates the need for external components. The four open-drain outputs have weak (10µA) internal pullups to VCC, allowing them to interface easily with other logic devices. The MAX6338 can monitor power supplies with either 5% or 10% tolerance specifications, depending on the selected version. An additional high-input-impedance comparator option can be used as an adjustable voltage monitor, general-purpose comparator, or digital level translator. The weak internal pullups can be overdriven by external pullups to any voltage from 0 to +5.5V. Internal circuitry prevents current flow from the external pullup voltage to VCC. The outputs can be wire-ORed for a single “power good” signal. The MAX6338 has either one or two auxiliary inputs and two or three factory-programmed threshold voltages, or four fixed voltages. The inverting input of all compara4 tors is connected to a 1.23V bandgap reference for all positive voltages. The noninverting terminals are accessible through internal resistive voltage-dividers with preset factory threshold voltages. In the case of auxiliary (AUX) input, the positive terminal of the comparator is accessible directly for setting the threshold for the monitored voltage. When any of the inputs (IN1–IN4) are higher than the threshold level, the output is high. The output goes low as the input drops below the threshold voltage monitor. The undervoltage lockout circuitry remains active and the outputs remain low with VCC down to 1V (Figure 1). Applications Information Hysteresis When the voltage on one comparator input is at or near the voltage on the other input, ambient noise generally causes the comparator output to oscillate. The most common way to eliminate this problem is through hysteresis. When the two comparator input voltages are equal, hysteresis causes one comparator input voltage to move quickly past the other, thus taking the input out of the region where oscillation occurs. Standard comparators require hysteresis to be added through the use of external resistors. The external resistive network usually provides a positive feedback to the input in order to cause a jump in the threshold voltage when _______________________________________________________________________________________ Quad Voltage Monitor in µMAX Package MAX6338 VCC MAX6338M/N/O/P IN1 OUT1 VCC IN2 OUT2 VCC IN3* (AUX)* OUT3 VCC IN4 (-5V) OUT4 VREF REFERENCE VCC UNDERVOLTAGE LOCKOUT *SEE AUXILIARY INPUT SECTION. Figure 1. MAX6338 Functional Diagram _______________________________________________________________________________________ 5 MAX6338 Quad Voltage Monitor in µMAX Package +5V +5V 0.1µF* VCC V1 IN1 V2 IN2 V3 IN3 V4 IN4 MAX6338 VCC VIN (+5V) D1 IN1 IN2 OUT1 OUT1 MAX6338 D2 OUT2 D3 OUT2 IN3 OUT3 IN4 OUT4 OUT3 D4 OUT4 GND GND *OPTIONAL Figure 2. Quad Undervoltage Detector with LED Indicators +5V VTH1 = 1 + R2 VREF R1 ( ) OUT1 VCC R2 VREF = 1.23V Figure 3. VCC Bar Graph Monitoring IN1 R1 IN2 VTH1 OUT1 MAX6338HUB OUT2 OUT1 INPUT IN3 OUT3 OUT4 VTH4 R4 IN4 R3 OUT4 GND VTH4 = 1 + R4 VREF R3 ( ) OUT ∆VTH Figure 4. Window Detection Figure 5. Output Response of Window Detector Circuit output toggles in one direction or the other. These resistors are not required when using the MAX6338 because hysteresis is built into the device. MAX6338 hysteresis is typically 0.3%. The MAX6338 can also be used in applications such as system supervisory monitoring, multivoltage level detection, and VCC bar graph monitoring (Figure 3). Undervoltage Detection Circuit A window detector circuit uses two auxiliary inputs in a configuration such as the one shown in Figure 4. External resistors R1–R4 set the two threshold voltages (VTH1 and VTH4) of the window detector circuit. Window width (∆VTH) is the difference between the threshold voltages (Figure 5). The open-drain outputs of the MAX6338 can be configured to detect an undervoltage condition. Figure 2 shows a configuration where a low at a comparator output indicates an undervoltage condition, which in turn causes an LED to light. 6 Window Detection _______________________________________________________________________________________ Quad Voltage Monitor in µMAX Package R1 The unused inputs (except the auxiliary) are internally connected to ground through the lower resistors of the threshold-setting resistor pairs. The auxiliary (AUX) input, however, must be connected to either ground or VCC if unused. R2 The MAX6338 operates from a single +2.5V to +5.5V supply. In noisy applications, connect a 0.1µF capacitor on the supply voltage line close to V CC pin for bypassing. Power-Supply Bypassing and Grounding VREF = 1.23V R1 = R2 Chip Information INTH - 1) ( V1.23 TRANSISTOR COUNT: 620 PROCESS: BiCMOS Figure 6. Setting the Auxiliary Monitor Auxiliary Input The adjustable voltage monitor is comparable to an internal reference of 1.23V as shown in Figure 6. To set the desired trip level of monitored supply, V INTH , choose: R1 = R2 [(VINTH / 1.23) - 1)]. For example, for a voltage detection at 4.5V (assume R2 = 100kΩ), R1 = 265kΩ. Typical Operating Circuit +2.5V TO +5.5V (MAY BE ONE OF THE MONITORED VOLTAGES) VCC IN1 SUPPLIES TO BE MONITORED MAX6338 OUT1 IN2 OUT2 IN3 OUT3 IN4 OUT4 SYSTEM LOGIC µP GND _______________________________________________________________________________________ 7 MAX6338 Unused Inputs VINTH Quad Voltage Monitor in µMAX Package 10LUMAX.EPS MAX6338 Package Information 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. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.