asahi kasei [ak4250/52] rev.0.4 2006/11 - 1 - general description the ak4250/52 are a video amp with lpf. the output coupling capacitor can be removed because the ak4250/52 include the negative power supply circuit. the ak4250/52 are housed in a space-saving 8-pin uson package. feature 1. video function ? a composite video input ? a video-amp for composite video signal ak4250: +6db AK4252: +12db ? low pass filter ? charge pump circuit for negative power supply 2. ta = -40 85 c 3. power supply: 2.7 3.6v (typ. 3.0v) 4. power supply current: 10 ma 5. package: 8 pin uson ? block diagram vin clamp lpf vout vdd charge pump clock generator pdn cp cn vss vee figure 1. ak4250/52 block diagram a k4250 / 52 output coupling capacitor-less v ideo amp with lpf = preliminary =
asahi kasei [ak4250/52] rev.0.4 2006/11 - 2 - ? ordering guide ak4250vu ? 40 +85 c 8 pin uson (0.5mm pitch) AK4252vu ? 40 +85 c 8 pin uson (0.5mm pitch) akd4250/52 evaluation board for ak4250/52 ? pin layout 1 cp vdd top view 2 3 4 8 7 6 5 vin pdn vout vss vee cn
asahi kasei [ak4250/52] rev.0.4 2006/11 - 3 - pin/function no. pin name i/o function 1 cp o positive charge pump capacitor terminal pin 2 vdd - power supply pin. 3 vin i composite video signal input pin 4 pdn i power-down mode pin. internal pull down 100k . ? h ? : power up, ? l ? : power down. 5 vout o composite video signal driver pin 6 vss - ground pin 7 vee o negative voltage output pin for video amplifier 8 cn i negative charge pump capacitor terminal pin absolute maximum ratings (vss=0v; note1) parameter symbol min max units power supplies: vdd ? 0.3 4.0 v input current, any pin except supplies iin - 10 ma input voltage (note 2) vin ? 0.3 (vdd+0.3) or 4.0 v ambient temperature (powered applied) ta ? 40 85 c storage temperature tstg ? 65 150 c note 1. all voltages with respect to ground. note 2. vin, pdin pins. max is smaller value between (vdd+0.3)v and 4.0v vout pin becomes hi-z at pdn pin = ?l?. therefore vout pin is available to signal line from another device by wired-or. then the input signal to vout pin mustn?t exceeds this input voltage range. the voltage must not be applied to the cn pin. warning: operation at or beyond these limits may result in permanent damage to the device. normal operation is not guaranteed at these extremes. recommended operating conditions (vss=0v; note1) parameter symbol min typ max units power supplies vdd 2.7 3.0 3.6 v note 1. all voltages with respect to ground. * akm assumes no responsibility for the usag e beyond the conditions in this datasheet.
asahi kasei [ak4250/52] rev.0.4 2006/11 - 4 - analog chracteristics (ta=25 c; vdd =3.0v; vss = 0v; unless otherwise specified) parameter conditions min typ max units v input characteristics input voltage ak4250 - - 1.5 vpp AK4252 - - 0.75 vpp input sync chip clamp (note 3) ak4250 -0.386 -0.286 -0.186 v voltage AK4252 tbd -0.143 tbd v v output characteristics ( note 4 ) output gain vin=100khz, 0.2vpp ak4250 5.0 6.0 7.0 db vin=100khz, tbd vpp AK4252 tbd 12.0 tbd db maximum output voltage vin=100khz , thd=-30db ak4250 2.52 - - vpp AK4252 2.52 - - vpp s/n bw=100kh 6mhz, (note 5) ak4250 - 65 - db AK4252 - 62 - db secondary distortion vin=3.58mhz, 0.2vpp(sin wave) - -45 - db load resistance 140 150 - load capacitance c1(see figure 2) c2(see figure 2) - - - - 15 400 pf pf lpf frequency response response at 6.75mhz tbd -0.5 - db input= 0.2vpp, sin wave response at 27mhz - -40 tbd db (0db at 100khz) group delay |gd3mhz - gd6mhz| - 10 tbd nsec power supplies power up black signal is output and no load resistance. - 10 tbd ma power down pdn pin = 0v - 1 tbd a note 3. the charge pump circuit doesn?t work well, if the sync chip clamp voltage input to vin pin isn?t within this voltage range. this sync chip clamp voltage is the voltage from the pedestal voltage note 4. the measurement point is the point a in figure 2 note 5. the reference signal is the 100% white signal. video signal output 75 ohm 75 ohm c2 r1 r2 c1 measurement point a figure 2. load capacitance c1 and c2 dc chracteristics (ta=25 c; vdd=2.7 3.6v) parameter symbol min typ max units high-level input voltage (pdn pin) low-level input voltage (pdn pin) vih vil 1.5 - - - - 0.6 v v
asahi kasei [ak4250/52] rev.0.4 2006/11 - 5 - ? video block the video amp has a drivability for a load resistance of 150 . the ak4250/52 have a composite input and output and includes a low pass filter (lpf). internal negative power supply circuit supplies the negative voltage to the video amp and th e video amp 0v output is used for a pedestal level. therefore, the output coupling capacitor can be removed. vdd charge pump cp cn vss vee 1uf 1uf negative power ak4250/52 (+) c2 c1 (+) note 6. c1 and c2 capacitors should have the low esr ( equivalent series resistance ) over all temperature range. when these capacitors have the polar ity, the positive polarity pin should be connected to the cp pin and the vss pin. non polarity capacitors can also be used. figure 3. negative power supply circuit vout 75 a k4250/52 0v 75 figure 4. video signal output ? power down control when the pdn pin is ?l?, the ak4250/52 are forced to the power down mode (power consumption: typ 1 a). vout pin becomes hi-z at pdn pin = ?l?. the ak4250/52 include a powe r-on-reset function. therefore any reset isn?t required externally.
asahi kasei [ak4250/52] rev.0.4 2006/11 - 6 - system design figure 5 shows the system connection diagram for the ak4250/52. an evaluation board [akd4250/52] is available which demonstrates the optimum layout, power supply arrangements and measurement results. top vie w power supply 2 .7 3.6v dsp or p + 10 vdd 2 vin 3 pdn 4 cp 1 75 0.1u 8 7 6 5 cn vee vss vout 1 0.1 1 (+) (+) figure 4. typical connection diagram note: - the voltage must not be applied to the cn pin.
asahi kasei [ak4250/52] rev.0.4 2006/11 - 7 - package 8pin uson (unit : mm) 2.2 0.05 2.2 0.05 0.05 0.6max 1.2 0.05 1.9 0.05 0.25 0.05 0.5 0.2 0.05 0.05 m we recommend mounting this portion onto circui t b oard in order to secure mounting intensity. please do not connect to a power supply, gnd, signal line, etc. ? material & lead finish package molding compound: epoxy lead frame material: ni lead frame surface treatment: ag plate
asahi kasei [ak4250/52] rev.0.4 2006/11 - 8 - marking ? ak4250vu 250 x xx 1 xxx: date code (3 digit) ? AK4252vu 252 x xx 1 xxx: date code (3 digit)
asahi kasei [ak4250/52] rev.0.4 2006/11 - 9 - important notice ? these products and their specifications are subject to change without notice. before considering any use or application, consult the asahi kasei microsystems co., ltd. (akm) sales office or authorized distributor concerning their current status. ? akm assumes no liability for infringement of any patent, intellectual property, or other right in the application or use of any information contained herein. ? any export of these products, or devices or systems containing them, may require an export license or other official approval under the law and regulations of the country of export pertaining to customs and tariffs, currency exchange, or strategic materials. ? akm products are neither intended nor authorized for use as critical components in any safety, life support, or other hazard related device or system, an d akm assumes no responsibility relating to any such use, except with the express written consent of the representative director of akm. as used here: a. a hazard related device or system is one designed or intended for life support or maintenance of safety or for applications in medicine, aerospace, nuclear energy, or other fields, in which its failure to function or perform may reasonably be expected to result in loss of life or in significant injury or damage to person or property. b. a critical component is one whose failure to function or perform may reasonably be expected to result, whether directly or indirectly, in the loss of the safety or effectiveness of the device or system containing it, and which must therefor e meet very high standards of performance and reliability. ? it is the responsibility of the buyer or distributor of an akm product who distributes, disposes of, or otherwise places the product with a third party to notify that party in advance of the above content and conditions, and the buyer or distributor agrees to assume any and all responsibility and liability for and hold akm harmless from any and all claims arising from the use of said product in the absence of such notification.
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