telefunken semiconductors U2781B-FS 1 rev. a2: 14.03.1995 frequency synthesizer description the programmable frequency synthesizer ic u2781b for m p controlled application is realized with telefunken advanced uhf process, which is very suitable for combinations of fast ecl logic and low current i 2 l logic. the benefits are high input sensitivity in connection with low power consumption and therefore small packages (sso-20). this feature makes the device very suitable for cordless phones and handheld cellular radio sets up to 1.1 ghz. features very low current consumption (typ. 3 v/ 5 ma) supply voltage range: 2.7 v 5.5 v max. input frequency: 1.1 ghz programmable prescaler 64/ 65 or 128/ 129 controlled by 3-wire-bus with f clock up to 500 khz status output for pll lock/ unlock condition very fast phase detector sso-20 package esd protection in accordance with mil-std. 883 methode 3015 class 2 benefits very low current consumption extends talk time few external components and sso package save costs and space block diagram charge pump prescaler 64/65 128/129 v v s 18 bit shift register phase detector oscillator 14 bit reference counter data clock osci gnd 1 bit latch load control ps cp ldo mo rfi enable 7 bit swallow counter 15 bit latch 11 bit main 18 bit latch counter scp 93 7785 e osco 17 3 15 1 8 11 7 4 10 6 14 13 5
telefunken semiconductors U2781B-FS 2 rev. a2: 14.03.1995 functional description the ic is controlled by a 3-wire-bus with the inputs for clock, data and enable for programming the scaling factors of the programmable counter, the reference counter and the prescaler. a tcxo can be connected to the oscillator input (osci) as an alternative solution to the common crystal reference oscillator. in that case the oscillator output (osco) should be left open. the charge pump output operates as switched current sources. the characteristics of the phase locked loop can be determinated by the external low pass filter. the phase characteristic of the phase detector is convertible and so matchable to different frequency/ tuning voltage characteristics. pin description pin symbol function 1 osci oscillator input 2 n.c. not connected 3 osco oscillator output 4 v scp charge pump supply voltage 5 v s supply voltage 6 cp charge pump output 7 gnd ground 8 ldo lock detector output 9 n.c. not connected 10 rfi vco input pin symbol function 11 clock 3-wire-bus clock 12 n.c. not connected 13 data 3-wire-bus data 14 enable 3-wire-bus enable 15 ps phase select input 16 n.c. not connected 17 mo monitor output for f p and f r 18 n.c. not connected 19 n.c. not connected 20 n.c. not connected absolute maximum ratings parameters symbol value unit supply voltage v s 0.3 to 6 v rf input v rf v s v oscillator input voltage v osci 1 v oscillator output voltage v osco 1.5 v bus input voltage v bus 6 v phase select input voltage v ps 6 v charge pump input voltage v scp 6 v ambient temperature t amb 40 to 85 c storage temperature t stg 40 to 125 c operating range parameters symbol value unit supply voltage v s 2.7 to 5.5 v ambient temperature t amb 40 to 80 c thermal resistance parameters symbol value unit junction-ambient sso-20 r thja 140 k/w
telefunken semiconductors U2781B-FS 3 rev. a2: 14.03.1995 electrical characteristics t amb = 25 c, v s = 2.7 to 5.5 v, unless otherwise specified parameters test conditions / pin symbol min typ max unit dc supply supply voltage v s 2.7 5.5 v supply current v s = 3 v i s 5 ma supply voltage cp v scp v s 5.5 v supply current cp v cp = 5 v, pll in locked condition i scp 1 m a rf input input voltage f i = 200 to 1100 mhz r s = 50 w *) r s = 50 w *) v imin v imax 20 200 mv rm mv rmss frequency range f imin f imax 1100 50 1250 mhz mhz scaling factor prescaler s psc 64/128 scaling factors main counter s m 4 2047 scaling factors swallow counter s s 0 127 reference oscillator input voltage r s = 50 w *) r s = 50 w *) v imin v imax 20 200 mv rms mv rms frequency range f imin f imax 0,1 20 mhz mhz scaling factor reference counter s r 4 16383 3-wire bus (clock, data, enable) and ps highinput voltage v ih 1.5 0.9 v low-input voltage v il 0 0.4 v high-input current i ih 5 m a low-input current i il 5 m a monitor output (emitter follower) high-output voltage v s = 3 v v ih 2.1 2.2 v low-output voltage i mo = 0.5 ma v il 1.8 1.9 v charge pump output source current v cp = 5 v i source 1 ma sink current i sink 1 ma leakage current v cp = 5 v i leak 5 na lock detektor output (open collector) saturation voltage i ld = 1 ma v sat 0.2 0.4 v leakage current v ld = 5 v i leak 1 m a *) rms voltage at 50
telefunken semiconductors U2781B-FS 4 rev. a2: 14.03.1995 functional description reference and programmable counter can be programmed by the 3-wire bus (clock, data and enable). the data signal is transfered bit by bit during the rising edge into the shift register, starting with the msb-bit. as soon as the enable signal is in high condition the contents of the shift register will be taken over either into the 15 bit reference counter latch (c = h) or into the 18 bit latch of the programmable counter (c = l) reference counter (15bit shift register) lsb msb c r0 r1 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11 r12 r13 psc c: control bit high psc: prescaler scaling factor bit: high 64/65 low 128/129 s psc = 64 or 128 r0 to r13: these bits are setting the reference counter s r s r = r0 * 2 0 + r1 * 2 1 + to + r12 * 2 12 + r13 * 2 13 allowed scaling factors for s r : 4 to 16383 programmable counter (18bit shift register) lsb msb c s0 s1 s2 s3 s4 s5 s6 m0 m1 m2 m3 m4 m5 m6 m7 m8 m9 m10 c: control bit low s0 to s6: these bits are setting the swallow counter s s . s s = s0 * 2 0 + s1 * 2 1 + to + s5 * 2 5 + s6 * 2 6 allowed scaling factors for s s : 0 to 127, s s < s m m0 to m10 : these bits are setting the main counter s m . s m = m0 * 2 0 + m1 * 2 1 + to + m9 * 2 9 + m10 * 2 10 allowed scaling factors for s m : 4 to 2047 total scaling factor s p of the programmable counter s p = (s psc * s m ) + s s condition: s s < s m vcofrequency f vco = ((s psc * s m ) + s s ) * f refosc / s r
telefunken semiconductors U2781B-FS 5 rev. a2: 14.03.1995 timing 3-wire-bus c = 1 : reference scaler date 93 7787 e msb t 5 t 4 t 3 t 2 t 1 lsb c = 0 : prog. scaler data r 0 p 0 r 6 p 8 r 7 p 9 r 13 p 16 psc p 17 enable clock data all times t1 ... t5 > = 1 phase detector polarity the polarity of the phase detector can be changed with the ps input. depending on the ps input level the charge pump current will also be inverted. the monitor output signal mo (emitter follower output with ecl level) will be switched over from f p to f r simultanously. ps = high or open ps = low cp mo cp mo f r > f p i sink f r i source f p f r < f p i source f r i sink f p f r = f p 0 f r 0 f p depending on the vco frequency versus tuning voltage characteristic the ps input has to be programmed as follows: for increasing tuning voltage and increasing frequency: ps = high or open decreasing frequency: ps = low. pulse diagram phase and lock detector v ld fp (fvco/tp) 93 7786 e cp fr (fosc/tr) the ld output is in unlocked condition at low level and the pulsewidth is in reference to the phase respectively frequency difference at the phase detector. if the phase detector output pulses are smaller than 100 ns the ld output goes high and indicates alocko condition.
telefunken semiconductors U2781B-FS 6 rev. a2: 14.03.1995 test circuit input sensitivity 94 8904 monitor frequency counter rf test generator data clock enable 10 k u2781b 1n 10 n 1 v s = 3 v typical input sensitivity 93 7789 e rms mv 65 60 55 50 45 40 35 30 +10 + 5 25 20 15 10 5 frequency ( mhz ) dbm ( 50 ohm) 0 200 400 600 800 1000 0 1600 1400 1200 .1 .2 1 2 5 10 20 50 100 200 500 1000 .5 ( 50 ohm)
telefunken semiconductors U2781B-FS 7 rev. a2: 14.03.1995 application circuit 94 8905 loop filter 1 1 alternatively to extern tcxo tuning voltage 10n 10n 2*10p ld vco u2781b 1n 10k 10n enable clock data v scp = 3 to 6 v v s = 3 v
telefunken semiconductors U2781B-FS 8 rev. a2: 14.03.1995 dimensions in mm package: sso-20 we reserve the right to make changes to improve technical design without further notice . parameters can vary in different applications. all operating parameters must be validated for each customer application by the customer. should the buyer use temic products for any unintended or unauthorized application, the buyer shall indemnify temic against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. temic telefunken microelectronic gmbh, p.o.b. 3535, d-74025 heilbronn, germany telephone: 49 ( 0 ) 7131 67 2831, fax number: 49 ( 0 ) 7131 67 2423
telefunken semiconductors U2781B-FS 9 rev. a2: 14.03.1995 ozone depleting substances policy statement it is the policy of temic telefunken microelectronic gmbh to 1. meet all present and future national and international statutory requirements and 2. regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. of particular concern is the control or elimination of releases into the atmosphere of those substances which are known as ozone depleting substances ( odss). the montreal protocol ( 1987) and its london amendments ( 1990) will soon severely restrict the use of odss and forbid their use within the next ten years. various national and international initiatives are pressing for an earlier ban on these substances. temic telefunken microelectronic gmbh semiconductor division has been able to use its policy of continuous improvements to eliminate the use of any odss listed in the following documents. 1. annex a, b and list of transitional substances of the montreal protocol and the london amendments respectively 2 . class i and ii ozone depleting substances in the clean air act amendments of 1990 by the environmental protection agency ( epa ) in the usa and 3. council decision 88/540/eec and 91/690/eec annex a, b and c ( transitional substances ) respectively. temic can certify that our semiconductors are not manufactured with and do not contain ozone depleting substances.
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