DS1640/DS1640c personal computer power fet DS1640/DS1640c 022698 1/4 features ? contains four p channel power fet switches that can each supply over 300 ma @ 0.2 volts drop ? controlled directly from cmos or ttl level signals ? fast switching time of less than 10 m s at rated supply current ? 16-pin dip or 16-pin soic surface mount package ? positive logic signal turns each fet on and ground or low level signal turns each fet off ? off condition allows less than 50 na of current flow ? low control gate capacitance of less than 5 pf ? fet gates can either follow inputs or be latched ? designed for use with power supplies ranging from +3 to +5 volts pin assignment 16-pin dip (300 mil) in4 gate4 out4 nc v cc out3 gate3 in3 in1 gate1 out1 latch gnd out2 gate2 in2 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 16-pin soic (300 mil) 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 in4 gate4 out4 nc v cc out3 gate3 in3 in1 gate1 out1 latch gnd out2 gate2 in2 see mech. drawings see mech. drawings section section pin description v cc - +3 to +5 volt input gnd - ground in1-in4 - fet sources out1-out4 - fet drains gate1-gate4 - fet control gates nc - no connection latch - gate inputs latch control description the DS1640 contains four p channel power mos fet's designed as switches to conserve power in personal computer systems. when connected to power man- agement control units, power consuming devices like disk drives or display panel backlights can be routinely shut down to conserve battery or main power supply en- ergy. the p channel power mos fet's are individually controlled and are capable of handling 300 ma each continuously with less than 0.2 volts drop from input to output. the device requires a +3 ? +5 volt power supply input which is used to power internal logic and to oper- ate a gate bias generator.
DS1640/DS1640c 022698 2/4 operation with +3 ? +5 volts applied between the v cc pin and ground, any one of four inputs can be connected or dis- connected from its respective output based on the bias applied to the control gate (see figure 1). a set of four internal latches is controlled by the latch input. the logic levels passed to the fet gates are controlled by the gate inputs and latch pin status. when the latch pin is logic 0, the gate input levels are inverted and passed di- rectly to the control gates, enabling the switches to be switched both independently and asynchronously. with a transition from logic 0 to logic 1 on the latch pin, the input levels present on the gate inputs are locked by the four internal latches, maintaining the corresponding fet gates at those levels. as long as the latch input is maintained at logic 1, the fet gate levels are main- tained. when the latch input is returned to logic 0, the gate inputs again are inverted and passed to the fet control gates without being latched. a ttl or cmos logic 1 turns a switch completely on and ttl or cmos logic 0 turns a switch completely off. the four switches can be operated independently or two or more can be connected in parallel for added current carrying capabil- ity. the four switches contained within the DS1640 are not designed to be operated in a linear manner. when v cc is not applied to the DS1640 or if v cc is not within nominal limits, the output levels and current carrying ca- pability of the four switches are not guaranteed. when all four gate inputs are off (logic 0) the device enters a low v cc current standby mode because the onboard charge pump is turned off. the gate and latch inputs are cmos-compatible throughout the entire v cc range and are ttl-compatible when v cc falls between 4.5 and 5.5v. DS1640 block diagram figure 1 out1 in1 gate1 substrate charge pump latch v cc latch out2 in2 out3 in3 out4 in4 gate2 latch gate3 latch gate4 latch
DS1640/DS1640c 022698 3/4 absolute maximum ratings* voltage on any pin relative to ground 0.3v to +7.0v operating temperature 0 c to 70 c storage temperature 55 c to +125 c soldering temperature 260 c for 10 seconds * this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. dc operating conditions (0 c to 70 c) parameter symbol min typ max units notes supply voltage v cc 3.0 5.5 v 1, 2 logic 0 input 3.0 v < v cc < 4.5 v v il2 -0.3 +0.5 v logic 0 input 4.5 v < v cc < 5.0 v v il1 -0.3 +0.8 v 1 logic 1 input 3.0 v < v cc < 5.0 v v ih 2.0 v cc +0.5 v 1, 7 source voltage v source v cc +0.5 v 1, 7 dc electrical characteristics (0 c to 70 c; v cc = +5v + 10%) parameter symbol min typ max units notes supply current i cc1 0.3 1 ma 3 supply current i cc2 0.1 1 m a 4 switch off leakage i sl 100 na switch on resistance r on 0.3 .67 w switch current @ v f = 200 mv i s 300 ma 5 input leakage i il -1 +1 m a 6 gate input capacitance c g 5 pf 7 ac electrical characteristics (0 c to 70 c; v cc = +5v + 10%) parameter symbol min typ max units notes switching time (off on) t ston 10 m s switching time (on off) t stoff 10 m s minimum time to engage latch t lm 50 ns
DS1640/DS1640c 022698 4/4 notes: 1. all voltages are referenced to ground. 2. when v cc is below minimum limits output levels are not guaranteed. 3. i cc1 is the supply current with one or more switches on. 4. i cc2 is when all switches are off and all inputs are within 0.5v of a supply rail. 5. each switch is capable of carrying 300 ma maximum at 200 mv forward drop. 6. input leakage applies to the four gate inputs and the latch input only. 7. applies to each of four gate inputs and the latch input. dallas semiconductor devices are built to the highest quality standards and manufactured for long term reliability. all DS1640 devices are made using the same quality materials and manufacturing methods. however, consumer ver- sions of the DS1640 are not exposed to environmental stresses that some commercial device manufacturing flows require. devices that are designated as consumer product have a aco designator in the product number. for exam- ple, the DS1640c is a consumer grade product.
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