1 industrial temperature range idt74fst1632861 20-bit, two port bus switch with resistor june 2006 industrial temperature range the idt logo is a registered trademark of integrated device technology, inc. ? 2006 integrated device technology, inc. dsc-5582/4 features: ? bus switches provide zero delay paths ? low switch on-resistance: 28 ? ttl-compatible input and output levels ? esd > 2000v per mil-std-883, method 3015; > 200v using machine model (c = 200pf, r = 0) ? hot insertion capability ? very low power dissipation ? available in ssop, tssop, and tvsop packages functional block diagram idt74fst1632861 20-bit, two port bus switch with resistor description: the fst1632861 belongs to idt's family of bus switches. bus switch devices perform the function of connecting or isolating two ports without providing any inherent current sink or source capability. they generate little or no noise of their own while providing a low resistance path for an external driver. these devices connect input and output ports through an n-channel fet. when the gate-to-source junction of this fet is adequately forward-biased, the device conducts and the resistance between input and output ports is small. with-out adequate bias on the gate-to-source junction of the fet, the fet is turned off, therefore with no v cc applied, the device has hot insertion capability. the fst1632861 bus switch has a built-in 28 series resistor to reduce noise which can result from reflections. this 28 built-in series resistor eliminates the need for an external terminating resistor. 1 oe a 0 a 1 a 2 a 3 b 0 b 1 b 2 b 3 a 4 a 5 a 6 a 7 b 4 b 5 b 6 b 7 a 8 a 9 b 8 b 9 2 oe a 10 a 11 a 12 a 13 b 10 b 11 b 12 b 13 a 14 a 15 a 16 a 17 b 14 b 15 b 16 b 17 a 18 a 19 b 18 b 19
2 industrial temperature range idt74fst1632861 20-bit, two port bus switch with resistor ssop/ tssop/ tvsop top view pin configuration symbol description max unit v term (2) terminal voltage with respect to gnd ?0.5 to +7 v t stg storage temperature ?65 to +150 c i out maximum continuous channel current 128 ma absolute maximum ratings (1) notes: 1. stresses greater than those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. 2. vcc, control, and switch terminals. symbol parameter conditions (2) typ. unit c in control input capacitance 6 pf c i/o switch input/output capacitance switch off 12 pf capacitance (1) notes: 1. capacitance is characterized but not tested. 2. t a = 25c, f = 1mhz, v in = 0v, v out = 0v. a 0 a 2 a 3 a 5 a 8 a 10 a 11 a 14 a 17 a 1 a 4 a 6 a 7 a 9 gnd nc a 12 a 13 a 15 a 18 a 19 a 16 gnd 1 oe v cc 39 29 30 31 32 33 34 35 36 37 38 25 26 27 28 48 47 41 42 43 44 45 46 40 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 19 20 11 21 22 23 24 nc b 0 b 2 b 3 b 5 b 8 b 10 b 11 b 14 b 17 b 1 b 4 b 6 b 7 b 9 vcc 2 oe b 12 b 13 b 15 b 18 b 19 b 16 note: 1. h = high voltage level l = low voltage level function table (1) inputs x oe outputs l connect a to b h disconnect a from b pin names description x oe output enable inputs (active low) a x a port bits b x b port bits pin description
3 industrial temperature range idt74fst1632861 20-bit, two port bus switch with resistor symbol parameter test conditions (1) min. typ. (2) max. unit v ih control input high voltage guaranteed logic high for control inputs 2 ? ? v v il control input low voltage guaranteed logic low for control inputs ? ? 0.8 v i ih control input high current v cc = max. v i = v cc ?? 1a i il control input low current v i = gnd ? ? 1 i ozh current during v cc = max., v o = 0 to 5v ? ? 1a i ozl bus switch disconnect ? ? 1 v ik clamp diode voltage v cc = min., i in = ?18ma ? ?0.7 ?1.2 v i off switch power off leakage v cc = 0v, v in or v o 5.5v ? ? 1a i cc quiescent power supply current v cc = max., v in = gnd or v cc ? 0.1 3 a dc electrical characteristics over operating range following conditions apply unless otherwise specified: industrial: t a = ?40c to +85c, v cc = 5.0v 10% bus switch impedance over operating range following conditions apply unless otherwise specified: industrial: t a = -40c to +85c, v cc = 5.0v 10% symbol parameter test conditions min. typ. (1) max. unit r on switch connect resistance, v in = 0v, i on = 48ma 20 28 40 a to b (2) v in = 2.4v, i on = 15ma 20 35 48 i os short circuit current, a to b (3) a(b) = 0v, b(a) = vcc 100 ? ? ma notes: 1. typical values are at vcc = 5.0v, +25c ambient. 2. the voltage drop between the indicated ports divided by the current through the switch. 3. not more than one output should be shorted at one time. duration of the test should not exceed one second.
4 industrial temperature range idt74fst1632861 20-bit, two port bus switch with resistor symbol parameter test conditions (1) min. typ. (2) max. unit i cc quiescent power supply current v cc = max. ? 0.5 1.5 ma ttl inputs high v in = 3.4v (3) i ccd dynamic power supply v cc = max. v in = v cc ? 30 400 a / current (4,5) outputs open v in = gnd mhz/ select input togging select 50% duty cycle i c total power supply current (6) v cc = max. v in = v cc ? 0.6 8 ma outputs open v in = gnd two enable pins toggling v in = 3.4v ? 0.7 9.5 f i = 10mhz v in = gnd 50% duty cycle power supply characteristics notes: 1. for conditions shown as max. or min., use appropriate value specified under electrical characteristics for the applicable dev ice type. t a = ?40c to +85c 2. typical values are at v cc = 5.0v, +25c ambient. 3. per ttl driven input (v in = 3.4v). all other inputs at v cc or gnd. switch inputs do not contribute to i cc. 4. this parameter represents the current required to switch the internal capacitance of the control inputs at the specified freq uency. switch inputs generate no significant power supply currents as they transition. this parameter is not directly testable, but i s derived for use in total power supply calculations. 5. c pd = i ccd /v cc c pd = power dissipation capacitance 6. i c = i quiescent + i inputs + i dynamic i c = i cc + i cc d h n t + i ccd (f i n) i cc = quiescent current i cc = power supply current for a ttl high input (v in = 3.4v) d h = duty cycle for ttl inputs high n t = number of ttl inputs at d h i ccd = dynamic current caused by an input transition pair (hlh or lhl) f i = control input frequency n = number of control inputs toggling at f i switching characteristics over operating range following conditions apply unless otherwise specified: industrial: t a = -40c to +85c, v cc = 5.0v 10% v cc = 5v 10% v cc = 4v symbol description (1) min. typ. max. max. unit t plh data propagation delay ? ? 0.25 0.25 ns t phl a to b, y to b (2) t pzh switch connect delay 1.5 ? 6.5 7 ns t pzl x oe to a or b t phz switch disconnect delay 1.5 ? 7 7 ns t plz x oe to a or b |q ci | charge injection during switch disconnect, ? 1.5 ? ? pc x oe to a or b (3) notes: 1. see test circuits and waveforms. 2. the bus switch contributes no propagation delay other than the rc delay of the load interacting with the rc of the switch. 3. |q ci | is the charge injection for a single switch disconnect and applies to either single switches or multiplexers. |q dci | is the charge injection for a multiplexer as the multiplexed port switches from one path to another. charge injection is reduced because the injection from the disconnect of the first pat h is compensated by the connect of the second path.
5 industrial temperature range idt74fst1632861 20-bit, two port bus switch with resistor d.u.t. v cc 1 mhz signal generator c l = 50pf (3) v out switch out enable/select switch in switch in (mux) (1) (2) pulse generator r t d.u.t. v cc v in c l v out 50pf 500 500 7.0v 3v 1.5v 0v 3v 1.5v 0v 3v 1.5v 0v 3v 1.5v 0v data input timing input asynchronous control synchronous control t su t h t rem t su t h high-low-high pulse low-high-low pulse t w 1.5v 1.5v same phase input transition 3v 1.5v 0v 1.5v v oh t plh output opposite phase input transition 3v 1.5v 0v t plh t phl t phl v ol control input 3v 1.5v 0v 3.5v 0v output normally low output normally high switch closed switch open v ol 0.3v 0.3v t plz t pzl t pzh t phz 3.5v 0v 1.5v 1.5v enable disable v oh test circuits and waveforms propagation delay test circuits for all outputs enable and disable times set-up, hold, and release times pulse width notes: 1. diagram shown for input control enable-low and input control disable-high. 2. pulse generator for all pulses: rate 1.0mhz; t f 2.5ns; t r 2.5ns. test switch open drain disable low closed enable low all other tests open switch position definitions: c l = load capacitance: includes jig and probe capacitance. r t = termination resistance: should be equal to z out of the pulse generator. charge injection notes: 1. select is used with multiplexers for measuring iq dci i during multiplexer select. during all other tests enable is used. 2. used with multiplexers to measure iq dci i only. 3. charge injection = v out c l , with enable toggling for iq ci i or select toggling for iq dci i. v out is the change in v out and is measured with a 10m probe.
6 industrial temperature range idt74fst1632861 20-bit, two port bus switch with resistor ordering information idt xx temp. range xxx device type xx package 74 ?40c to +85c pv pvg pa pag pf pfg 2861 shrink small outline package ssop - green thin shrink small outline package tssop - green thin very small outline package tvsop - green 20-bit flow through switch with resistor fst xxx family 163 double-density bus switch corporate headquarters for sales: for tech support: 6024 silver creek valley road 800-345-7015 or 408-284-8200 logichelp@idt.com san jose, ca 95138 fax: 408-284-2775 www.idt.com
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