1 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer april 2001 2001 integrated device technology, inc. dsc 5174/5 c commercial and industrial temperature ranges the idt logo is a registered trademark of integrated device technology, inc. features: ? phase-lock loop clock distribution ? 10mhz to 133mhz operating frequency ? distributes one clock input to one bank of five outputs ? zero input-output delay ? output skew < 250ps ? low jitter <200 ps cycle-to-cycle ? idt2305-1 for standard drive ? idt2305-1h for high drive ? no external rc network required ? operates at 3.3v v dd ? power down mode ? available in soic package functional block diagram idt2305 3.3v zero delay clock buffer pll 8 clk1 clk2 clk3 clk4 control logic ref clkout 1 3 2 5 7 description: the idt2305 is a high-speed phase-lock loop (pll) clock buffer, designed to address high-speed clock distribution applications. the zero delay is achieved by aligning the phase between the incoming clock and the output clock, operable within the range of 10 to 133mhz. the idt2305 is an 8-pin version of the idt2309. idt2305 accepts one reference input, and drives out five low skew clocks. the -1h version of this device operates, up to 133mhz frequency and has a higher drive than the -1 device. all parts have on-chip plls which lock to an input clock on the ref pin. the pll feedback is on-chip and is obtained from the clkout pad. in the absence of an input clock, the idt2305 enters power down. in this mode, the device will draw less than 25 a, the outputs are tri-stated, and the pll is not running, resulting in a significant reduction of power. the idt2305 is characterized for both industrial and commercial operation. note: for new designs, refer to an-233.
2 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer ref clk1 2 3 4 8 7 6 5 1 clk2 gnd clkout clk4 v dd clk3 pin configuration soic top view symbol rating max. unit v dd supply voltage range ?0.5 to +4.6 v v i (2) input voltage range (ref) ?0.5 to +5.5 v v i input voltage range ?0.5 to v (except ref) v dd +0.5 i ik (v i < 0) input clamp current ?50 ma i o (v o = 0 to v dd ) continuous output current 50 ma v dd or gnd continuous current 100 ma t a = 55c maximum power dissipation 0.7 w (in still air) (3) t stg storage temperature range ?65 to +150 c operating commercial temperature 0 to +70 c temperature range operating industrial temperature -40 to +85 c temperature range 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. the input and output negative-voltage ratings may be exceeded if the input and output clamp-current ratings are observed. 3. the maximum package power dissipation is calculated using a junction temperature of 150c and a board trace length of 750 mils. notes: 1. weak pull down. 2. weak pull down on all outputs. pin description absolute maximum ratings (1) applications: ? sdram telecom datacom pc motherboards/workstations critical path delay designs pin name pin number type functional description ref (1) 1 in input reference clock, 5 volt tolerant input clk2 (2) 2 out output clock clk1 (2) 3 out output clock gnd 4 ground ground clk3 (2) 5 out output clock v dd 6 pwr 3.3v supply clk4 (2) 7 out output clock clkout (2) 8 out output clock, internal feedback on this pin
3 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer symbol parameter min. max. unit v dd supply voltage 3 3.6 v t a operating temperature (ambient temperature) 0 70 c c l load capacitance < 100mhz ? 30 pf load capacitance 100mhz - 133mhz ? 10 c in input capacitance ? 7 pf operating conditions - commercial dc electrical characteristics - commercial symbol parameter conditions min. max. unit v il input low voltage level ? 0.8 v v ih input high voltage level 2 ? v i il input low current v in = 0v ? 50 a i ih input high current v in = v dd ? 100 a v ol output low voltage standard drive i ol = 8ma ? 0.4 v high drive i ol = 12ma (-1h) v oh output high voltage standard drive i oh = -8ma 2.4 ? v high drive i oh = -12ma (-1h) i dd_pd power down current ref = 0mhz ? 12 a i dd supply current unloaded outputs at 66.66mhz ? 32 ma switching characteristics (2305-1) - commercial (1,2) symbol parameter conditions min. typ. max. unit t 1 output frequency 10pf load 10 ? 133 mhz 30pf load 10 ? 100 duty cycle = t 2 t 1 measured at 1.4v, f out = 66.66mhz 40 50 60 % t 3 rise time measured between 0.8v and 2v ? ? 2.5 ns t 4 fall time measured between 0.8v and 2v ? ? 2.5 ns t 5 output to output skew all outputs equally loaded ? ? 250 ps t 6 delay, ref rising edge to clkout rising edge measured at v dd /2 ? 0 350 ps t 7 device-to-device skew measured at v dd /2 on the clkout pins of devices ? 0 700 ps t j cycle-to-cycle jitter, pk - pk measured at 66.66mhz, loaded outputs ? ? 200 ps t lock pll lock time stable power supply, valid clock presented on ref pin ? ? 1 ms notes: 1. ref input has a threshold voltage of v dd /2. 2. all parameters specified with loaded outputs.
4 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer symbol parameter min. max. unit v dd supply voltage 3 3.6 v t a operating temperature (ambient temperature) -40 +85 c c l load capacitance < 100mhz ? 30 pf load capacitance 100mhz - 133mhz ? 10 c in input capacitance ? 7 pf operating conditions - industrial switching characteristics (2305-1h) - commercial (1,2) symbol parameter conditions min. typ. max. unit t 1 output frequency 10pf load 10 ? 133 mhz 30pf load 10 ? 100 duty cycle = t 2 t 1 measured at 1.4v, f out = 66.66mhz 40 50 60 % duty cycle = t 2 t 1 measured at 1.4v, f out <50mhz 45 50 55 % t 3 rise time measured between 0.8v and 2v ? ? 1.5 ns t 4 fall time measured between 0.8v and 2v ? ? 1.5 ns t 5 output to output skew all outputs equally loaded ? ? 250 ps t 6 delay, ref rising edge to clkout rising edge measured at v dd /2 ? 0 350 ps t 7 device-to-device skew measured at v dd /2 on the clkout pins of devices ? 0 700 ps t 8 output slew rate measured between 0.8v and 2v using test circuit #2 1 ? ? v/ns t j cycle-to-cycle jitter, pk - pk measured at 66.66mhz, loaded outputs ? ? 200 ps t lock pll lock time stable power supply, valid clock presented on ref pin ? ? 1 ms notes: 1. ref input has a threshold voltage of v dd /2. 2. all parameters specified with loaded outputs. dc electrical characteristics - industrial symbol parameter conditions min. max. unit v il input low voltage level ? 0.8 v v ih input high voltage level 2 ? v i il input low current v in = 0v ? 50 a i ih input high current v in = v dd ? 100 a v ol output low voltage standard drive i ol = 8ma ? 0.4 v high drive i ol = 12ma (-1h) v oh output high voltage standard drive i oh = -8ma 2.4 ? v high drive i oh = -12ma (-1h) i dd_pd power down current ref = 0mhz ? 25 a i dd supply current unloaded outputs at 66.66mhz ? 35 ma
5 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer switching characteristics (2305-1h) - industrial (1,2) symbol parameter conditions min. typ. max. unit t 1 output frequency 10pf load 10 ? 133 mhz 30pf load 10 ? 100 duty cycle = t 2 t 1 measured at 1.4v, f out = 66.66mhz 40 50 60 % duty cycle = t 2 t 1 measured at 1.4v, f out <50mhz 45 50 55 % t 3 rise time measured between 0.8v and 2v ? ? 1.5 ns t 4 fall time measured between 0.8v and 2v ? ? 1.5 ns t 5 output to output skew all outputs equally loaded ? ? 250 ps t 6 delay, ref rising edge to clkout rising edge measured at v dd /2 ? 0 350 ps t 7 device-to-device skew measured at v dd /2 on the clkout pins of devices ? 0 700 ps t 8 output slew rate measured between 0.8v and 2v using test circuit #2 1 ? ? v/ns t j cycle-to-cycle jitter, pk - pk measured at 66.66mhz, loaded outputs ? ? 200 ps t lock pll lock time stable power supply, valid clock presented on ref pin ? ? 1 ms notes: 1. ref input has a threshold voltage of v dd /2. 2. all parameters specified with loaded outputs. switching characteristics (2305-1) - industrial (1,2) symbol parameter conditions min. typ. max. unit t 1 output frequency 10pf load 10 ? 133 mhz 30pf load 10 ? 100 duty cycle = t 2 t 1 measured at 1.4v, f out = 66.66mhz 40 50 60 % t 3 rise time measured between 0.8v and 2v ? ? 2.5 ns t 4 fall time measured between 0.8v and 2v ? ? 2.5 ns t 5 output to output skew all outputs equally loaded ? ? 250 ps t 6 delay, ref rising edge to clkout rising edge measured at v dd /2 ? 0 350 ps t 7 device-to-device skew measured at v dd /2 on the clkout pins of devices ? 0 700 ps t j cycle-to-cycle jitter, pk - pk measured at 66.66mhz, loaded outputs ? ? 200 ps t lock pll lock time stable power supply, valid clock presented on ref pin ? ? 1 ms notes: 1. ref input has a threshold voltage of v dd /2. 2. all parameters specified with loaded outputs.
6 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer ref to clka/clkb delay (ps) zero delay and skew control all outputs should be uniformly loaded in order to achieve zero i/o delay. since the clkout pin is the internal feedback for th e pll, its relative loading can affect and adjust the input/output delay. the output load difference diagram illustrates the pll's relative loading with respect to the other outputs that can adjust the input-output (i/o) delay. for designs utilizing zero i/o delay, all outputs including clkout must be equally loaded. even if the output is not used, it m ust have a capacitive load equal to that on the other outputs in order to obtain true zero i/o delay. if i/o delay adjustments are needed, use the o utput load difference diagram to calculate loading differences between the clkout pin and other outputs. for zero output-to-output skew, all outputs must be loaded equally. ref to clka/clkb relay vs. output load difference between clkout pin and clka/clkb pins output load difference between clkout pin and clka/clkb pins (pf) 1500 1000 500 0 -500 -1000 -1500 -30 -25 -20 -15 -10 -5 05 10 15 20 25 30
7 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer v dd outputs v dd gnd gnd 0.1 f 0.1 f v dd outputs 10pf v dd gnd gnd 0.1 f 0.1 f 1k ? 1k ? c load clk out clk out output 1.4v 1.4v t5 output ref v dd/ 2 t6 output clk out device 1 t7 clk out device 2 v dd/ 2 v dd /2 v dd /2 1.4v 1.4v t2 t1 1.4v 2v 0.8v t3 t4 0.8v 3.3v 0v 2v output all outputs rise/fall time input to output propagation delay device to device skew output to output skew duty cycle timing switching waveforms test circuit 1 (all parameters except t8) test circuit 2 (t8, output slew rate on -1h devices) test circuits
8 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer typical duty cycle (1) and i dd trends (2) for idt2305-1 notes: 1. duty cycle is taken from typical chip measured at 1.4v. 2. i dd data is calculated from i dd = i core + ncvf, where i core is the unloaded current. (n = number of outputs; c = capacitance load per output (f); v = supply voltage (v); f = frequency (hz)) 3 3.1 3.2 3.3 3.4 3.5 3.6 v dd (v) 40 42 44 46 48 50 52 54 56 58 60 duty cycle vs v dd (for 30pf loads over frequency - 3.3v, 25c) 33mhz 66mhz 100mhz d u t y c y c l e ( % ) 3 3.1 3.2 3.3 3.4 3.5 3.6 v dd (v) 40 42 44 46 48 50 52 54 56 58 60 duty cycle vs v dd (for 10pf loads over frequency - 3.3v, 25c) 33mhz 66mhz 100mhz 20 40 60 80 100 120 140 frequency (mhz) 40 42 44 46 48 50 52 54 56 58 60 duty cycle vs frequency (for 30pf loads over temperature - 3.3v) -40c 0c 25c 70c 85c d u t y c y c l e ( % ) d u t y c y c l e ( % ) 133mhz 20 40 60 80 100 120 140 frequency (mhz) 40 42 44 46 48 50 52 54 56 58 60 duty cycle vs frequency (for 10pf loads over temperature - 3.3v) -40c 0c 25c 70c 85c d u t y c y c l e ( % ) 02 4 6 8 number of loaded outputs 0 20 40 60 80 100 120 140 i dd vs number of loaded outputs (for 30pf loads over frequency - 3.3v, 25c) 33mhz 66mhz 100mhz i d d ( m a ) 02 4 6 8 number of loaded outputs 0 20 40 60 80 100 120 140 i dd vs number of loaded outputs (for 10pf loads over frequency - 3.3v, 25c) 33mhz 66mhz 100mhz i d d ( m a )
9 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer typical duty cycle (1) and i dd trends (2) for idt2305-1h notes: 1. duty cycle is taken from typical chip measured at 1.4v. 2. i dd data is calculated from idd = icore + ncvf, where icore is the unloaded current. (n = number of outputs; c = capacitance load per output (f); v = supply voltage (v); f = frequency (hz)) 3 3.1 3.2 3.3 3.4 3.5 3.6 v dd (v) 40 42 44 46 48 50 52 54 56 58 60 duty cycle vs v dd (for 30pf loads over frequency - 3.3v, 25c) 33mhz 66mhz 100mhz d u t y c y c l e ( % ) 3 3.1 3.2 3.3 3.4 3.5 3.6 v dd (v) 40 42 44 46 48 50 52 54 56 58 60 duty cycle vs v dd (for 10pf loads over frequency - 3.3v, 25c) 33mhz 66mhz 100mhz 20 40 60 80 100 120 140 frequency (mhz) 40 42 44 46 48 50 52 54 56 58 60 duty cycle vs frequency (for 30pf loads over temperature - 3.3v) -40c 0c 25c 70c 85c d u t y c y c l e ( % ) d u t y c y c l e ( % ) 133mhz 20 40 60 80 100 120 140 frequency (mhz) 40 42 44 46 48 50 52 54 56 58 60 duty cycle vs frequency (for 10pf loads over temperature - 3.3v) -40c 0c 25c 70c 85c d u t y c y c l e ( % ) 02 4 6 8 number of loaded outputs 0 20 40 60 80 100 120 140 i dd vs number of loaded outputs (for 30pf loads over frequency - 3.3v, 25c) 33mhz 66mhz 100mhz i d d ( m a ) 02 4 6 8 number of loaded outputs 0 20 40 60 80 100 120 140 i dd vs number of loaded outputs (for 10pf loads over frequency - 3.3v, 25c) 33mhz 66mhz 100mhz i d d ( m a ) 160 160
10 commercial and industrial temperature ranges idt2305 3.3v zero delay clock buffer ordering information ordering code package type operating range idt2305-1dc 8-pin soic commercial IDT2305-1DCG 8-pin soic commercial idt2305-1dci 8-pin soic industrial IDT2305-1DCGi 8-pin soic industrial idt2305-1hdc 8-pin soic commercial idt2305-1hdci 8-pin soic industrial corporate headquarters for sales: for tech support: 2975 stender way 800-345-7015 or 408-727-6116 logichelp@idt.com santa clara, ca 95054 fax: 408-492-8674 (408) 654-6459 www.idt.com idt xxxxx xx x package process device type 2305-1 2305-1h zero delay clock buffer high drive output dc dcg small outline soic - green blank i commercial (0 o c to +70 o c) industrial (-40 o c to +85 o c)
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