SC1460 ? 1999 semtech corp. 652 mitchell road newbury park ca 91320 5ma capless tm charge pump preliminary - july 6, 1999 1 block diagram pin configuration 3 lead sot-23 description the SC1460 is a versatile charge pump designed for use in battery operated power supply applications re- quiring up to 5ma. it enables a simple low current boost circuit to be implemented without the costly in- ductors or capacitors associated with regular switching circuits. features include internal mosfets, control circuitry and charge pump capacitor, requiring only two external capacitors for a total solution. with a very high operating frequency (8mhz free running at 2.5v in typically), the SC1460 does not require large input or output capacitors, and therefore uses very little board space. two versions of the SC1460 are available: the -3.3 produces a regulated 3.3v output from 2.5v in, and the -5.0 produces a regulated 5v output from 3.3v in. it is supplied in the popular 3 lead, sot-23 pack- age. features ? small size - sot-23 package ? 4% voltage accuracy ? typical 100ua quiescent current tel:805-498-2111 fax:805-498-3804 web:http:// www.semtech.com ordering information device (1)(2) package SC1460csk-x.x sot-23 notes: (1) where x.x denotes voltage options. available volt- ages are: 3.3v and 5.0v. (2) add suffix ?tr? for tape and reel. absolute maximum ratings parameter symbol maximum units supply voltage vin -0.3 to + 4 v output voltage vo -0.3 to +6.0 v thermal resistance junction to ambient ja 410 c/w operating temperature t a 0 to +70 c temperature range t j 0 to 125 c storage temperature t stg -65 to +150 c lead temperature (soldering) 10 seconds t l 300 c applications ? handheld power supplies ? pda power supplies ? notebook power supplies ? peripheral card supplies ? industrial power supplies ? high density dc/dc conversion (top view)
SC1460 ? 1999 semtech corp. 652 mitchell road newbury park ca 91320 5ma capless tm charge pump preliminary - july 6, 1999 2 electrical characteristics unless specified: vin = 3.3v (-5.0 parts), vin = 2.5v (-3.3 parts), 0 i o 4ma, c in = 0.22uf, c out = 47nf, t a = 25c. values in bold apply over full operating temperature range parameter symbol conditions min typ max units input supply voltage vin 2.25 3.63 v input supply current i in i o = 0ma vin = 2.5 v 100 150 a output voltage vo SC1460csk - 3.3, vin = 2.5v -4 1.32 x vin 4 % SC1460csk - 5.0, vin = 3.3v 4 1.515 x vin 4 % output ripple (pk-pk) v r i o = 4ma, c out = 47nf 50 mv output current i o 45 ma efficiency i o = 4ma 50 56 % oscillator frequency osc SC1460csk - 3.3, vin = 2.5v 8 mhz SC1460csk - 5.0, vin = 3.3v 8.75 time to regulation at turn-on t on power up with i o = 4ma 100 s application circuit vin vo u1 SC1460 1 2 3 gnd vo vin cin 0.22uf cout 47nf
SC1460 ? 1999 semtech corp. 652 mitchell road newbury park ca 91320 5ma capless tm charge pump preliminary - july 6, 1999 3 typical iin vs. vin @25 deg. c. 0 2 4 6 8 10 12 14 16 22.533.54 vin (v) iin (ma) io = 6 ma io = 5 ma io = 4 ma io = 0 ma typical iin vs. io @25 deg. c. 0 2 4 6 8 10 12 14 16 0123456 io (ma) iin (ma) vin = 3.60v vin = 3.30v vin = 2.50v vin = 2.25v typical vo vs. io @25 deg. c. 2 2.5 3 3.5 4 4.5 5 0123456 io (ma) vo (v) vin = 3.60v vin = 3.30v vin = 2.50v vin = 2.25v typical eff. vs. io @25 deg. c. 45 50 55 60 44.555.56 io (ma) efficiency (%) vin = 2.25v vin = 2.50v vin = 3.30v vin = 3.60v typical eff. vs. vin @25 deg. c. 45 50 55 60 22.533.54 vin (v) efficiency (%) io = 4ma io = 5ma io = 6ma typical eff. vs. vo @25 deg. c. 45 50 55 60 2.5 3 3.5 4 4.5 5 vo (v) efficiency (%) io = 4 ma io = 5 ma io = 6 ma
SC1460 ? 1999 semtech corp. 652 mitchell road newbury park ca 91320 5ma capless tm charge pump preliminary - july 6, 1999 4 typical vo vs. vin @25 deg. c. 2 2.5 3 3.5 4 4.5 5 22.533.54 vin (v) vo (v) io = 0 ma io = 4 ma io = 5 ma io = 6 ma
SC1460 ? 1999 semtech corp. 652 mitchell road newbury park ca 91320 5ma capless tm charge pump preliminary - july 6, 1999 5 vo ripple typical vo ripple vs. cout @ vin = 2.50v 000.0e+0 10.0e-3 20.0e-3 30.0e-3 40.0e-3 50.0e-3 60.0e-3 70.0e-3 22.0e-9 47.0e-9 56.0e-9 68.0e-9 82.0e-9 180.0e-9 220.0e-9 cout (f) vo ripple (v) iout = 4ma typical iin vs. ta @ io = 0 ma 0.05 0.07 0.09 0.11 0.13 0.15 0.17 0.19 0 10203040506070 ta (deg. c.) iin (ma) vin = 2.25 v vin = 2.50 v vin = 3.30 v vin = 3.60 v typical vo vs. ta @ vin = 2.50v 2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5 0 10203040506070 ta (deg. c.) vo (v) io = 0ma io = 4ma io = 5ma io = 6ma typical eff. vs. ta @ io = 4 ma 53 54 55 56 57 0 1020304050607080 ta (deg. c.) efficiency (%) vin = 2.25 v vin = 2.50 v vin = 3.30 v vin = 3.60 v
SC1460 ? 1999 semtech corp. 652 mitchell road newbury park ca 91320 5ma capless tm charge pump preliminary - july 6, 1999 6 outline drawing sot-23-3l
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