AN8353UB PANASONIC | Alldatasheet

Document overview

  • Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 4

Technical content

The AN8353UB is a dimmer IC to control illumination of the car dashboard at high efficiency and high performance by pulse width control. It outputs pulses at a duty proprotional to an input voltage. n Features

  • Low power consumption by pulse control
  • External ON/OFF control by the standby pin
  • Pulse frequency range : 50Hz to 10kHz
  • Built-in overvoltage protective circuit approx. 20V
  • Wide operating ambient temperature range : –40˚C to+100˚C
  • All products temperature cycle, high reliability by normal and high temperature checks reliability equivalent to the air bags requested in U.S. AN8353UB High Efficiency Car Dashboard Dimmer IC 0.3 + 0.1 – 0.05 23.3–0.3 6.0–0.3 2.4–0.25 3.3–0.25 1.5–0.25 0.5–0.1 2.54 1.5–0.25 1.4–0.3 30˚ 3.0–0.3 Unit : mm 9-pin SIL Plastic Package (SIP009-P-0000C) 6 5 7 8 V CC Control Voltage Conversion Over Voltage Protector GND PWM Comparator Triangular Wave Gen. n Block Diagram

Pin N o. Pin nam e n Pin D escriptions D escription

1 O utput pin O utputs an interm ittent source current at a duty proportional to an input voltage

2 G N D G N D

3 Input pin A pplies a control voltage. 4 N oise elim inating capacity connection pin 1 C onnect a capacitor to elim inator a noise. 7 N oise elim inating capacity connection pin 2 C onnect a capacitor to elim inator a noise.

9 V C C Supply V oltage

5 Square w ave output pin

6 Triangular w ave output pin

8 Standby pin

O utput a triangular w ave, w hich serves as a reference for the PW M signal, to the Pin6 by connecting the resistor R T betw een the Pins5 and6, and capacity C T betw een the Pin6 and G N D . O utput a triangular w ave, w hich serves as a reference for the PW M signal, to this pin by connecting the resistor R T betw een the Pins6 and 5, and capasity C T betw een the Pin6 and G N D . Forces to shut off an output current if a voltage higher than a threshold voltage of 1.1V is applied to the Pin8. V C C PD Topr Tstg Supply voltage Pow er dissipation Storage tem perature O perating am bient tem perature V m W Param eter Sym bol R ating U nit n A bsolute M axim um R atings (Ta=25˚C ) 550 –40 to +100 –50 to +150 Param eter Sym bol R ange n R ecom m ended O perating R ange (Ta=25˚C ) O perating supply voltage range V C C 8 to 18V Param eter Sym bol C ondition m in typ m ax n Electrical C haracteristics (Ta=25˚C ) Supply current IC C 11 m A7.5Elim inate C T and R T O scillation frequency fosc H z115C T=0.027µF 0% duty input voltage V IN – 0 3 V2.5C T=0.027µF 100% duty input voltage V IN – 100 VC T=0.027µF C enter duty (V C C =12V ) D 12V %45C T=0.027µF %C T=0.027µFC enter duty (V C C =8V ) D D 8V %0C T=0.027µF C enter duty (V C C =18V ) D D 18V %50C T=0.027µFO utput duty gain D G VO utput voltage at O N V O N µA0 C T=2100pF Leakage current at O FF IL V20 C T=2100pF 1.65 1.2 10.5 140 0.6 9.5 O ver voltage detection voltage V O V C T=2100pF V1.1C T=2100pFStandby threshold voltage V STH 0.9 0.55 U nit

180Ω (3W ) 10kΩ 10kΩ 2kΩ C T R T 20kΩ 180kΩ V R 20kΩ 180kΩ V R 0.056µF 0.056µF 0.1µF 0.1µF C T R T 0.1µF 0.1µF 33µF22V 33µF22V 2 3 4 5 6 7 98 1 2 3 4 5 6 7 98 1/fO SC =1.705R TC T 1/fO SC =1.705R TC T

  • B ipolar Transister O utput • M O S FET O utput n Application Circuit n Supplem entary D escription
  • System O perational Principle The follow ing describes the operational principle of the system using the A N 8353U B . A s show n in the block diagram in Fig. 1, a battery voltage is divided by the V R and input to the input Pin3 in accord- ance w ith rotation am ount. The voltage at the output Pin1 is controlled by the A N 8353U B so that the duty of the O N /O FF period of the external output transistor w ill be proportional to the input voltage, thus controlling a current flow ing to the lam ps of the dashboard, etc. to adjust their brightness. Since the output transistors are saturated at O N tim e and no current flow s at O FF tim e, pow er consum ption is low . The PW M m ethod is used to control the output transistors. This m ethod, as show n in Fig. 2 I/O C haracteristic C hart (III), generates the triangular w ave V 6 as a reference signal to generate pulses and input them to one end (Pin6) of the PW M com parator. The triangular w ave frequency fO SC can be freely set from 50H z to 10kH z, depending on the resistance value R T connected betw een the square w ave output Pin5 and triangular w ave output Pin6, and capacity value C T connected betw een the triangular w ave output Pin6 and ground Pin2. The approxim ating expression for the then PW M frequency fO SC is ; For your refence, Fig. 3 show s the relations am ong C T, R T, and oscillation frequency fO SC . The voltage V 4, w hose voltage level is m ade m atching the am plitude of the triangular w ave by the control voltage converter, is given to the other input (Pin4) of the PW M com parator. That is, in Fig. 2 (II), the input voltage V 3 is linearly converted into V 4 by the control voltage converter so that the am plitude of the triangular w ave w ill be about 20% to 80% of the input voltage input range (axis of abscissas in Fig. 2 (II)). Then, a current is supplied from the output Pin1 to turn on the output transistors during the period (TO N ) w hen the inverted input voltage is larger than the triangular w ave. (Fig. 2 (II), (IV )) To the contrary, w hile the converted input voltage is sm aller than the triangular w ave, no current is supplied from the output Pin1 and the output transistors are turned off. The output pulse duty is expressed as follow s. For the duty control characteristic of the output pulses to the input voltage V 3, the duty of the output pulses is controlled from 0% to 100% at high-precision linearity w hile the “input voltage V 3/supply voltage V 9” is betw een about 6 5 7 8 C ontrol voltage converting circuit O ver voltage protection PW M com pa- rator Tranguian w aveform generator 0.1µF C 1 R T C T 0.1µF STB C 2 33µF 2kΩ 10kΩ B attery Fig. 1 A N 8353U B B lock D iagram

0.2 (B -point) and 0.8 (C -point). The A -point in the figure show s the I/O characteristics w hen the “input voltage V 3/sup- ply voltage V 9” is 0.7. A nd, w hen V 3/V 9 is from 0.05V to about 0.2V (B -point), the duty is controlled to 0% , and w hen V 3/V 9 is from 0.8V (C -point) to t.0V , the duty is controlled to 100% . The standby Pin8 can forcibly turn off the output transistors by applying a voltage of about 1.1V or m ore to this pin. W hen it is not necessary to forcibly turn off the output tran- sistors, Leave the standby Pin8 open.

  • System O perational Principle (cont.)
  • O ver voltage D etecting V oltage vs. O utput n Supplem entary D escription (cont.) D 1 V 9–2 V O V 50%
  • Standby Threshold V oltage vs. O utput
  • D uty D 1 vs. Input V oltage V IN (V C C =12V ) D 1 V 8–2 V STH0 50% D 1 V IN V 3/V 9 V 3/V 9 V 4/V 9 V 4/V 9 V 6/V 9 m ax V 6/V 9 V 1 t TO N D uty=TO N · fO SC 1/fO SC t 10.5 0.5 1 B B ´ A ´ C ´ 100% 50% 0.5 D uty (I) (III) (IV ) (II) Turn-up Line Fig. 2 I/O C haracteristic C hart Fig. 3 R elations betw een O scillation Frequency and C T and R T A C V IN –0 V IN –1004V 6V 8V 100% D 12VD G
  • O utput voltage at O N V O N · Leakage current at O FF V O N =V C C –V 1–2 IL= V 1–2 IM Ω m ax V 6/V 9 R esistance R T (Ω ) O scillation Frequency fO SC (H z) 100k 10k 100 10k 100k 1M 10M V C C =12V V IN =6V C T=0.001µF C T=0.01µF C T=0.1µF C T=1µF