GMT1555/1557 GMT1555 GMT1557 GMT1555S GMT1557S 00E-01 00E-03 00E-02 00E-06

Great GMT Mixed Signal Technologies TIMER/OSCILLATOR DESCRIPTION FEATURES The GMT1555/1557 Timer/Oscillator devices are designed

GMT1555/1557 GMT1555/1557 Great GMT Mixed Signal Technologies TIMER/OSCILLATOR DESCRIPTION FEATURES The GMT1555/1557 GMT1555/1557 Timer/Oscillator devices are designed to offer the one-shot or oscillator user the specific function needed, in the smallest possible package. The classic 555 timer, now in a SOT 23-5 package, has been split into two simple parts: the 1555 monostable and the 1557 astable device. This design has been executed in a BCDMOS process, allowing for significant power reduction when compared to the bipolar 555 device. One-shot pulse widths are available over the wide range of 0.1 mSec to several hours, and oscillation frequencies of up to 5.0 MHz are easily obtainable. Duty cycles other than 50% are easily commanded with only a few external components (refer to the applications section). Both devices operate over the broad supply voltage range of +2.7 V to +18 V, and feature a unique built-in logic lockout to provide a controlled, well behaved turn-on characteristic. · · · · · · · Built in logic lock-out to ensure stable turn-on. Broad range Vcc; +2.7 V to +18 V operation. Low Current Consumption = 110 uA typical with a 5.0 V supply. TTL compatible I/O. Compact SOT 23-5 package. Resistant to supply and temperature variations. 1.0 uA sleep mode (1557 only, CS forced low). Figure 2: Figure 1: +5.0 V 1 +5.0 V VS OUT 3 4 TRG 2 GND Output R THR GMT1555 GMT1555 - ONE-SHOT VS OUT 5 3 CS 2 5 C Page 1 of 9 GMT Microelectronics 4 GND R T/T 1 C GMT1557 GMT1557 - OSCILLATOR/TIMER Rev. 1.4. 1999-07-01 22-001-700 GMT1555/1557 GMT1555/1557 TIMER/OSCILLATOR ABSOLUTE MAXIMUM RATINGS OPERATING RATINGS Supply Voltage(VS).+20 V Supply Voltage (VS).+2.7 V to +18 V Threshold Voltage (VTHR, VT/T).+20 V Package Thermal Resistance Trigger Voltage (VTRG, VT/T).+20 V SOT-23-5 JA.220°C/W Ambient Temperature Range.-40°C to +85°C Lead Temperature, Soldering.260°C for 10 seconds OUT GND CS GND T/T 2 3 VS 1 3 2 1 G1 G2 GMT1555 GMT1555 4 4 THR TRG 5 GMT1557 GMT1557 5 VS OUT Table 1: PIN DESCRIPTION PIN NO. GMT1555 GMT1555 PIN NO. GMT1557 GMT1557 FUNCTION 1 4 VS 2 2 GND 3 CS 5 OUT Output: CMOS totem-pole output. 4 TRG Trigger (Input): Sets output high. Active low at < 1/3 VS nominal. 5 THR Threshold (Dominant Input): Sets output low. Active high at < 2/3 VS nominal. T/T Trigger/Threshold (Input): Internally connected to both threshold and trigger functions. See TRG and THR. 3 1 Rev. 1.4. 1999-07-01 22-001-700 DESCRIPTION Supply (Input) = 2.7 V to +18 V supply. Ground: supply return. Chip Select/Reset (Input): Active high at 2/3 VS. Output off (Sleep Mode) when CS is low (