SUPPLY VOLTAGE MONITOR ZSM330 ISSUE 1 – NOVEMBER 1995 DEVICE DESCRIPTION FEATURES The ZSM330 is a three terminal under vo l ta ge mo ni t or ci rc ui t f or use i n microprocessor systems. The threshold voltage of the device has been set to 3.1 volts making it ideal for 3.3 volt circuits. • • • • • • • Included in the device is a precise voltage reference and a comparator with built in hysteresis to prevent erratic operation. The ZSM330 features an open collector output capable of sinking at least l0mA which only requires a single external resistor to interface to following circuits. • • SO8, SOT223 and TO92 packages Power on reset generator Automatic reset generation Low standby current Guaranteed operation from 1 volt Wide supply voltage range Internal clamp diode to discharge delay capacitor 3.1 volt threshold for 3.3 volt logic 20mV hysteresis prevents erratic operation APPLICATIONS Operation of the device is guaranteed from one volt upwards, from this level to the device threshold voltage the output is held low providing a power on reset function. Should the supply voltage, once established, at any time drop below the threshold level then the output again will pull low. • • • • • • The device is available in a TO92 package for through hole applications as well as SO8 and SOT223 for surface mount requirements. SCHEMATIC DIAGRAM 4-344 Microprocessor systems Computers Computer peripherals Instrumentation Automotive Battery powered equipment ZSM330 ABSOLUTE MAXIMUM RATING Input Supply Voltage Offstate Output Voltage Onstate Output Sink Current(Note 1) Clamp Diode Forward Current(Note 1) Operating Junction Temperature Operating Temperature Storage Temperature -1 to 10V 10V Internally limited Power Dissipation TO92 SOT223 SO8 780mW 2W(Note 2) 780mW(Note 2) 100mA 150°C -40 to 85°C -55 to 150°C TEST CONDITIONS (Tamb=25°C for typical values, Tamb=-40 to 85°C for min/max values (Note3)) COMPARATOR MIN TYP. MAX. PARAMETER SYMBOL Threshold Voltage High state output (Vcc increasing) UNITS VIH 3.01 3.09 3.15 V Threshold Voltage Low state output (Vcc decreasing) VIL 3.01 3.07 3.15 V Hysteresis VH 0.01 0.02 0.05 V (Vcc=2.7V, Isink=8.0mA) 0.46 1.0 V (Vcc=2.7V, Isink=2.0mA) 0.15 0.4 V OUPUT Output sink saturation: VOL (Vcc=1.0V, Isink=0.1mA) Onstate output sink current (Vcc , Output=2.7V) Isink Offstate output leakage current (Vcc , Output=3.3V) Ioh Clamp diode forward voltage (If=10mA) Vf Propagation delay (Vin 3.3V to 2.7V, Rl=10k, Tamb=25°C) Td 10 0.6 0.25 V 27 60 mA 0.02 0.5 µA 1.2 1.5 V µs 2.2 TOTAL DEVICE Operating input voltage range Vcc Quiescent input current (Vcc=3.3V) Iq 1.0 to 6.5 V 120 180 µA Note: 1. Maximum package power dissipation must be observed 2. Maximum power dissipation, for the SOT223 and SO8 packages, is calculated assuming that the device is mounted on a PCB measuring 2 inches square. 3. Low duty cycle pulse techniques are used during test to maintain junction temperatures as close to ambient as possible 4-345 ZSM330 500 5 400 4 Output Voltage (V) Input Current (µA) TYPICAL CHARACTERISTICS 300 85 °C 200 -40 °C 100 25 °C 3 2 1 0 0 0 50 2 4 6 8 10 0 2 1 5 Input Voltage (V) Input Current vs. Input Voltage Output Voltage vs. Input Voltage Vin=2.7V RL=10K Vin (V) 3.3 2.7 2 30 -40 °C ' ' 4 25 °C 20 85 °C Vout (V) 2 10 0 0 0 0.4 0.8 1.2 1.6 0 2.0 1 4 Reset Delay Time Output Saturation Voltage vs. Sink Current 100 3 2 Time (µs) Output Saturation Voltage (V) 3.10 Vin=0V Upper Threshold 3.09 Threshold Voltage (V) 80 Forward Current (mA) 4 3 Input Voltage (V) 40 Sink Current (mA) R=10K TA=25°C 60 85 °C 25 °C 40 -40 °C 20 3.08 3.07 Lower Threshold 3.06 3.05 0 0 0.4 0.8 1.2 1.6 2.0 -40 -20 0 20 40 60 80 Temperature ( °C) Forward Voltage (V) Clamp Diode Forward Current vs. Voltage Threshold Voltage vs. Temperature 4-346 100 ZSM330 TIMING DIAGRAM Vcc Threshold Voltage 1V Output AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAAAAAA AAA AAAAAAA AAAA Output Undefined Output Undefined APPLICATION CIRCUIT Note 4: A time delayed reset can be accomplished with the additional Cd. 1 T DY = RCd ln V TH (mpu) 1 − Vin TDY =Time (Seconds) VTH =Microprocessor Reset Threshold Vin =Power Supply Voltage 4-347 ZSM330 CONNECTION DIAGRAMS SO8 Package Suffix – N8 SOT223 Top View Package Suffix – G Top View – Pin 4 floating or connected to pin 2 TO92 Package Suffix – C Bottom View ORDERING INFORMATION Part Number Package Part Mark ZSM330N8 SO8 ZSM330 ZSM330G SOT223 ZSM330 ZSM330C TO92 ZSM330 4-348