innovative products. active solutions. - 1 - www.active-semi.com copyright ? 2008 active-semi, inc. act8309/8310/8311 1.5a, pwm step-down dc/dcs in tdfn system blo ck diagram features ? multiple patents pending ? up to 95% high efficiency ? up to 1.5a guaranteed output current (act8311) ? 1.35mhz constant frequency operation ? internal synchronous rectifier eliminates schottky diode ? act8309: up to 900ma ? ACT8310: up to 1.2a ? act8311: up to 1.5a ? 100% duty cycle low-dropout operation ? 0.1a shutdown current ? small tdfn33-8 package ? rohs-compliant ? independent enable/disable control ? minimal external components applications ? wireless handhelds ? portable devices ? gps/pnd equipment general description the patent-pending act8309/ACT8310/act8311 are current-mode, fixed-fr equency pwm, synchro- nous step-down dc/dc conver ters that are capable of delivering 1.5a with efficiency of up to 95%. these devices operate with a fixed frequency of 1.35mhz, minimizing noise in sensitive equipment as well as optimizing both efficiency and component size and cost. these devices feature ve ry low-resistance power mosfet and 100% duty cycle operation, making them ideal choices for portable applications requir- ing a 3.0v or 3.3v rail to be generated from a li+ battery. the act8311 is capable of supplying up to 1.5a of output current, while the act8309 and ACT8310 are capable of supplying up to 900ma and 1.2a, respectively. all three devices have adjustable out- put voltages that are programmable down to 1.2v. contact active-semi for custom fixed output voltage availability. rev pra, 24-jan-08 advanced product information ? all information subject to change pb-free a ctive-semi act8311 in sw fb g v out up to 1.5a en on off pok gp 2.7v to 5.0v power-ok output a ctive- semi
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 2 - www.active-semi.com copyright ? 2008 active-semi, inc. ordering information part number output current package pins temperature range act8309nhadj-t tdfn33-8 8 -40c to +85c act8309nhxyz-t 0.9a tdfn33-8 8 -40c to +85c ACT8310nhadj-t 1.2a tdfn33-8 8 -40c to +85c 0.9a output voltage adjustable 1.2v, 1.5v, 1.8v, 2.5v, 3.0v, 3.3v c adjustable ACT8310nhxyz-t 1.2a 1.2v, 1.5v, 1.8v, 2.5v, 3.0v, 3.3v c tdfn33-8 8 -40c to +85c act8311nhadj-t 1.5a adjustable tdfn33-8 8 -40c to +85c act8311nhxyz-t 1.5a 1.2v, 1.5v, 1.8v, 2.5v, 3.0v, 3.3v c tdfn33-8 8 -40c to +85c pin configuration pin descriptions tdfn33-8 pin name description 1, 3 in power input. bypass to gp close to ic with a high quality ceramic capacitor. 2 gp power ground. connect to g with a short trace. 4 g analog ground. connect to gp with a short trace. 5 fb feedback node. for fixed output voltage versions , connect this pin directly to the output. for the adjustable output versions the voltage at this pin is regulated to 0.8v, connect to this pin to the center of the output feedback resistor divider for voltage setting. 6 pok open-drain power-ok status output. pok is an open-drain output which sinks current when the output voltage is less than 95% of the normal value. when the ic is disabled, pok is high impedance. 7 en enable input. when higher than 1.4v, this pin tu rns the ic on. when lower than 0.4v, this pin turn the ic off. 8 sw switch output. connect this pin to the switching end of the inductor. act8309 ACT8310 act8311 1 2 3 4 8 7 6 5 in gp g in sw pok fb en c : fixed output voltage options are available for production subject to minimum order quant ities. contact active-semi for more i nforma- tion regarding fixed output voltage options.
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 3 - www.active-semi.com copyright ? 2008 active-semi, inc. c : do not exceed these limits to prevent damage to the device. exposure to absolute maximum rati ng conditions for long periods m ay affect device reliability. parameter unit in, sw to gp v fb, en, pok to g v fb, en, sw voltage v gp to g v continuous sw current a junction to ambient thermal resistance ( ja ) c/w maximum power dissipation (derate 5.3mw/c above t a = 50c) w operating junction temperature c storage temperature c lead temperature (soldering, 10 sec) c value -0.3 to +5.5 -0.3 to +5.5 -0.3 to v in + 0.3 -0.3 to +0.3 internally limited 61 1.63 -40 to 150 -55 to 150 300 absolute maximum ratings c
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 4 - www.active-semi.com copyright ? 2008 active-semi, inc. parameter symbol test cond itions min typ max unit input voltage range v in 2.7 5.0 v under voltage lockout threshold v uvlo v in rising, hysteresis = 80mv 2.35 2.5 2.6 v standby supply current v fb = 103%v fb,typ , i out = 0 150 310 a shutdown supply current en = g, v in = 4.2v 0.1 1 a fb voltage v fb t a = 25c 0.786 0.80 0.814 v -40c < t a < 85c 0.776 0.80 0.824 output voltage accuracy t a = 25c -2% v nom +2% v -40c < t a < 85c -3% v nom +3% output voltage line regulation 0.06 0.4 %/v output voltage load regulation 0.6 % current limit act8309nh 1.1 1.3 1.8 a ACT8310nh 1.4 1.7 2.2 act8311nh 1.75 2.1 2.8 max output current act8309nh 0.9 a ACT8310nh 1.2 act8311nh 1.5 oscillator frequency f sw v out = 80% of v out,nom 1.05 1.35 1.6 mhz v fb = 0.1v 450 khz pmos on-resistance r onp act8309, i sw = -100ma 0.15 0.234 ACT8310, i sw = -100ma 0.12 0.192 act8311, i sw = -100ma 0.10 0.165 nmos on-resistance r onn i sw = 100ma 0.15 0.26 ? en logic high threshold v ih v in = 2.7v to 5.0v 1.4 v en logic low threshold v il v in = 2.7v to 5.0v 0.4 v en input bias current i en v in = 5.0v, en = g or in 0.01 0.1 a pok threshold % of v out,nom 95 % pok output low voltage v ol i pok = 100a 0.008 0.012 v pok leakage current i pok v pok = 5.0v 0.01 0.1 a ? electrical characteristics (v in = v en = 3.6v, t a = 25 ? c, unless otherwise specified.)
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 5 - www.active-semi.com copyright ? 2008 active-semi, inc. act8311 in sw fb g 3.0v up to 1.5a en in pok gp 2.7v to 5.0v out 100k? 3.3h 22f 549k? 200k? out 10f figure1: functional block diagram gate driver sw pwm control en in in gp fb pok g act8309 ACT8310 act8311 out out figure 2: typical application circuit a ctive-semi a ctive-semi 549k ? 200k ? 100k ?
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 6 - www.active-semi.com copyright ? 2008 active-semi, inc. ? ? ? ? ? ? ? ? ? = 1 v v r r fb out 2 fb 1 fb functional description the patent-pending act8309/ACT8310/act8311 are current-mode, fixed-fr equency pwm, synchro- nous step-down dc/dc conver ters that are capable of delivering up to 1.5a (act 8311) with efficiency of up to 95%. these devices feature very low- resistance power mosfets and 100% duty cycle operation, making them ideal choices for portable applications requiring a 3.0v or 3.3v rail to be gen- erated form a li+ battery. these device operate with a fixed frequency of 1.35mhz, minimizing noise in sensitive equipment as well as optimizing both efficiency and component size and cost. 100% duty cycle operation these devices are capabl e of operating at up to 100% duty cycle operation. during 100% duty cycle operation, the high-side power mosfet is held on continuously, providing a direct connection from the input to the output (thro ugh the inductor), ensuring the lowest possible dropout voltage in battery- powered applications. synchronous rectification the act8309/ACT8310/act8311 each feature integrated n-channel synchronous rectifiers, maxi- mizing efficiency and minimizing the total solution size and cost by eliminating the need for external rectifiers. soft-start the act8309/ACT8310/act8311 each include integrated soft-start circuitry. when enabled, the output voltage track an internal 200s soft-start ramp so that the output power up in a controlled, monotonic manner that is independent of loading. compensation the act8309/ACT8310/act8311 each utilize cur- rent-mode control and a proprietary internal compen- sation scheme to simultaneously simplify external component selection and optimize transient perform- ance over their full operating range. no compensation design is required, simply follow a few simple guide- lines described below when choosing external com- ponents. capacitor selection the input capacitor reduces peak currents and noise induced upon the voltage source. a 10f ceramic capacitor is recommended for most appli- cations. for most applications, a 22f ceramic output ca- pacitor is recommended. although the these regula- tors were designed to take advantage of the bene- fits of ceramic capacitors, namely small size and very-low esr, low-esr tantalum capacitors can provide acceptable results as well. inductor selection these devices were optimized for operation with 3.3h inductors, although inductors in the 1.5h to 4.7h range may be used. choose an inductors with a low dc-resistance, and avoid inductor satu- ration by choosing inductors with dc ratings that exceed the maximum output current of the applica- tion by at least 30%. output voltage setting figure 3 shows the feedbac k network necessary to set the output voltage when using adjustable output voltage options. output voltage options. select com- ponents as follows: set r fb2 = 200k ? , calculate r fb1 using the following equation: where v fb is 0.8v. figure 3: output voltage setting enable/disable control these devices may be enabled and disabled using the en input. drive en to a logic-high to enable the regulator, drive en to a logic-low to disable the regulator. when disabled, each regulator?s quies- cent supply current drops to less than 1a. power-ok output (pok) these devices feature an open-drain ?power-ok? indicator output. this output sinks current whenever the output voltage is (typic ally) 5% below the regu- lation voltage, and goes high-impedance when the output voltage is above this threshold. to generate fb act8309/ ACT8310/ act8311 v out r fb1 r fb2
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 7 - www.active-semi.com copyright ? 2008 active-semi, inc. a logic-level ?power-ok? signal, simply connect a pull- up resistor from pok to an appropriate output volt- age. pcb layout considerations high switching frequencies and large peak current make pc board layout an important part of step- down dc/dc converter design. a good design mini- mizes excessive emi on the feedback paths and volt- age gradients in the ground plane, both of which can result in instability or regulation errors. step-down dc/dcs exhibit discontinuous input current, so the input capacitors should be placed as close as possi- ble to the ic, and avoiding the use of vias if possible. the inductor, input filter c apacitor, and output filter capacitor should be connected as close together as possible, with short, direct, and wide traces. the ground nodes for each regulator?s power loop should be connected at a single point in a star-ground con- figuration, and this point should be connected to the backside ground plane with multiple vias. for fixed output voltage options the output node for each regu- lator should be connected to its corresponding fb pin through the shortest possible route, while keeping sufficient distance from switching nodes to prevent noise injection. adjustable output versions should follow the same guidelines, but additionally connect the feedback resistors to the fb pin as close to the ic as possible to minimize noise injection.
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 8 - www.active-semi.com copyright ? 2008 active-semi, inc. 0 200 400 600 800 1200 1000 900 800 700 600 500 400 300 200 100 0 typical performanc e characteristics (v in = v en = 3.6v, t a = 25c, unless otherwise specified.) act8309 efficiency vs. load current load current (ma) 1 dropout voltage (mv) load current (ma) act8309 dropout voltage vs. load current act8309/8310/8311-002 ACT8310 efficiency vs. load current efficiency (%) load current (ma) act8309/8310/8311-003 1 160 180 10 100 1000 10 100 1000 140 120 80 100 60 40 20 0 80 90 70 60 40 50 20 10 0 efficiency (%) act8311 efficiency vs. load current efficiency (%) load current (ma) act8309/8310/8311-005 1 10 100 1000 200 act8309/8310/8311-001 v out = 3.3v v out = 3.0v dropout voltage (mv) load current (ma) ACT8310 dropout voltage vs. load current act8309/8310/8311-004 160 180 140 120 80 100 60 40 20 0 200 v out = 3.3v v out = 3.0v 1.2 1.0 0.8 0.6 0.4 0.2 0 dropout voltage (mv) load current (ma) act8311 dropout voltage vs. load current act8309/8310/8311-006 160 180 140 120 80 100 60 40 20 0 200 v out = 3.3v v out = 3.0v 220 1.4 1.5 10000 10000 10000 30 100 v in = 3.6v v in = 3.6v v in = 3.6v v out = 3.3v v out = 3.0v v out = 1.8v v out = 1.2v v out = 3.3v v out = 3.0v v out = 1.8v v out = 1.2v v out = 3.3v v out = 3.0v v out = 1.8v v out = 1.2v 80 90 70 60 40 50 20 10 0 30 80 90 70 60 40 50 20 10 0 30 100 100
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 9 - www.active-semi.com copyright ? 2008 active-semi, inc. typical performanc e characteristics (v in = v en = 3.6v, t a = 25c, unless otherwise specified.) act8309/8310/8311-007 ch1: v out , 1.0v/div ch2: pok, 2.0v/div time: 100s act8309/8310/8311-008 startup waveform ch1 ch2 v out = 3.3v load transient response ch1: v out , 100mv/div (ac coupled) ch2: load current (100ma to 1000ma) time: 100s ch1 ch2 v in = 4.2v v out = 3.3v v in = 4.2v v out = 3.3v i out = 1a
act8309/8310/8311 rev pra, 24-jan-08 active- semi innovative products. active solutions. - 10 - www.active-semi.com copyright ? 2008 active-semi, inc. package outline active-semi, inc. reserves the right to modify the circuitry or spec ifications without notice. us ers should evaluate each produ ct to make sure that it is suitable for their applications. active-semi pr oducts are not intended or authorized for use as critical compon ents in life- support devices or systems. active-semi, inc. does not assume an y liability arising out of the use of any product or circuit de scribed in this datasheet, nor does it convey any patent license. active-semi and its logo are trademarks of active-semi, inc. for more information on this and other products, contact sales@active- semi.com or visit http://www.active-semi.com. for other inquiri es, please send to: 1270 oakmead parkway, suite 310, sunnyvale, california 94085-4044, usa tdfn33-8 package outline and dimensions symbol dimension in millimeters dimension in inches min max min max a 0.700 0.800 0.028 0.031 a1 0.000 0.050 0.000 0.002 a3 0.153 0.006 d 2.900 3.100 0.114 0.122 e 2.900 0.114 d2 2.200 0.087 e2 0.055 b 0.200 0.320 0.008 0.013 e 0.650 typ 0.026 typ l 0.375 0.575 0.015 0.023 1.400 3.100 0.122 0.253 0.010 2.400 1.600 0.094 0.063
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