BA9756FS Multimedia ICs High-voltage control circuit for CRT displays BA9756FS The BA9756FS is LSIs that control CRT anode voltage in multi-scan monitors and similar devices, using a chopper-type voltage control circuit. The internal sawtooth wave generator circuit uses automatic gain control (AGC) to enable coverage of a wide range from 30kHz to over 150kHz. The BA9756FS is equipped with an internal high-precision voltage source featuring an output voltage precision of ± 0.7%. !Block diagram !Applications CRT displays, HDTVs, others 20 19 18 17 16 15 VCC1 !Features 1) Internal chopper-type voltage control circuit. 2) Internal buffer circuit enables direct drive of Power MOSFET for output drive. 3) Internal high-precision voltage source offers output voltage precision of ± 0.7%. 11 – SAW GEN. 9.0V REF M/M GND 2 3 4 5 Symbol Limits Unit Power supply voltage 1 VCC1 18 V Power supply voltage 2 VCC2 20 V 750*1 Pd mW Operating temperature Topr - 25~+80 ˚C Storage temperature Tstg - 55~+125 ˚C *1 When mounted on a 70mm × 70mm × 1.6mm glass epoxy board. Reduced by 7.5mW for each increase in Ta of 1˚C over 25˚C. !Recommended operating conditions (Ta=25°C) Parameter 12 + + !Absolute maximum ratings (Ta=25°C) Power dissipation 13 Buffer – + 1 Parameter 14 VCC2 Symbol Min. Typ. Max. Unit Power supply voltage 1 VCC1 11 - 17 V Power supply voltage 2 VCC2 11 - 17 V 6 7 8 9 10 BA9756FS Multimedia ICs !Pin descriptions Pin No. 1 Pin name Function ERRIN This is the recovery voltage input pin. (error amplifier + input) 2 AGC (constant for AGC) 3 N.C. 4 SAWOUT (constant for sawtooth wave) 5 N.C. 6 Capacitance should be determined taking into consideration the linearity at the minimum oscillation frequency, and the response time when the frequency changes. See*1. This is the output pin for optimized sawtooth waves, based on the maximum oscillation frequency. fMax120kHz C = 1000pF fMax100kHz C = 1200pF fMax 80kHz C = 1500pF fMax 60kHz C = 2000pF See*1. MMCR A charging resistance of 4.7kΩ or higher should be used. (delay constant for The threshold level is 4.5V. monostable multivibrator) 7 HDIN (Hd pulse input) The threshold level is approximately 2.1V. 8 VREF9 (Ref 9V output) An output deviation of ± 0.7% is assured through trimming. 9 N.C. 10 GND (Signal GND) This may be shared with the power GND, but make sure sufficiently stable grounding is provided. 11 GND (Power GND) This may be shared with the signal GND, but make sure sufficiently stable grounding is provided. 12 PWMOUT (PWM output) If a voltage of less than GND or higher than VCC is applied because of external back electromotive force, a protective diode should be inserted (*2). If the protector circuit and thermal shutdown circuit are tripped, output is fixed at high (VCC) level. 13 N.C. 14 VCC2 (Power VCC) A decoupling capacitor should be positioned in the vicinity of this pin. 15 DTC IN (dead time control input) The voltage input to this pin enables restriction of the PWM output duty. The duty control is between 0V and 9V, and approximately 0% to 100% is enabled. At 0V, however, restrictions apply. The minimum pulse width for the PWM is 0.85µs (Typ. at 90kHz). 16 See*1. See*1. ERROUT This is the output pin for the error amplifier. (error amplifier output) 17 N.C. See*1. 18 N.C. See*1. 19 20 ERRREF This is the input pin for the reference voltage. (error amplifier input) VCC1 A decoupling capacitor should be positioned in the vicinity of this pin. (signal VCC) *1 N.C. pin processing In order to boost the thermal effect of the IC, we recommend connecting this to the GND or to an adjacent pin. *2 11 12 14 VCC2 + TO FET gate BA9756FS Multimedia ICs !Input / output circuits VCC VCC VCC 1 ERRIN 2 4 AGC SAW OUT Fig.1 Fig.2 VCC VCC 7 6 HDIN MMCR Fig.3 Fig.4 BA9756FS Multimedia ICs VCC2 VCC 14 8 VREG9 12 PWMOUT 11 PGND Fig.5 Fig.6 VCC1 VCC VCC 20 19 ERRREF 15 DTC 10 GND 16 ERROUT Fig.7 Fig.8 Fig.9 BA9756FS Multimedia ICs !Electrical characteristics (unless otherwise noted, Ta=25°C, Vcc=15V) Parameter Symbol Min. Typ. Max. Unit Conditions Test Circuit Input high level voltage VIH 3.0 - VCC V - Fig.10 Input low level voltage VIL - - 1.5 V - Fig.10 Input high level current IIH - 360 Input low level current IIL - 0 Tdl 1.80 HOS <Hd input pin> 530 µA -1 µA 2.15 2.50 µs 8.0 9.0 10.0 V Fig.10 VIN = 15V - Fig.10 <Monostable multivibrator> Delay time R = 10kΩ,C = 220pF Fig.10 <SAW GEN> Output high level - Fig.10 Output low level LOS 0 0.15 0.35 V Output level f characteristic fSAW 150 200 - kHz VREF9 8.937 9.0 9.063 V - Fig.10 Irmax9 10 - - mA - Fig.10 TREF9 - Tdow 100 -1dB drop from 30kHz Fig.10 <Reference voltage supply> Output voltage Max. output current Output voltage thermal characteristics Thermal shutdown ± 0.1 - ± 0.3 - % deg — Guaranteed design parameter Fig.10 at Ta = 25→0°C, 25→75°C Guaranteed design parameter Fig.10 BA9756FS Multimedia ICs !Measurement circuits Vs15 A Is12 2 1 2 1 SW12 SW15 V 20 19 18 17 16 15 14 13 12 11 VCC Buffer SAW GEN. 9.0V ref M/M GND 1 2 3 4 5 6 7 + 8 220µ 6V Vs6 1µ SW4 1 2 SW6 1 + 10 V A SW7 1500p SW8 10k 2 9 1 2 1 3 2 Is8 SG7 220p VCC Fig.10 1 5k 2 100k SWb 100k SWa 2 VCC 2 1 V SWc 1 100k SW1 1 16 6.8k SW16 1 Vs19 15µ + 2 16 1 Vs1 19 19 50 1 A 5.6k + V 10µ 2 50 SG1 Fig.11 50 Fig.12 BA9756FS Multimedia ICs !Measurement conditions (unless otherwise noted, Ta=25°C, Vcc=15V) Parameter Switch position Symbol Conditions SW1 SW3 SW4 SW5 SW6 SW9 SW11 SW12 SWa SWb SWc ICC - 1 1 1 1 1 1 - - - - - Input bias current IB 1 1 1 1 1 1 1 1 1 1 1 Vs1 = 6V, IB = - VIN ×10–5 Input offset voltage VIO 1 1 1 1 1 1 1 1 2 2 2 Vs1 = 6V, VIO = (V12 – 6) × 10–2 Output low level voltage VOL 1 1 1 1 1 1 1 1 2 1 1 Vs1 = 5V, Vs13 = 6V Output high level voltage VOH 1 1 1 1 1 1 1 1 2 1 1 Vs1 = 7V, Vs13 = 6V Open voltage gain AV - 1 1 1 1 1 1 - - - - SG1: f = 1kHz,VIN = 10mVP-P Max. output current IOM 1 1 1 1 1 1 1 2 2 1 1 Vs1 = 7V, Vs13 = 6V VOH - 2 1 1 1 2 2 - - - - Vs3 = 6V,Vs11 = 5V, Is9 = - 100mA 1 1 2 2 - Circuit current <Error amplifier> *1 <PWM amplifier> Output high level voltage Output low level voltage VOL - 2 1 - - - Vs3 = 6V,Vs11 = 7V, Is9 = ± 100mA Rise time Tr - 1 1 3 1 1 1 - - - - SG5: f = 90kHz *2 Fall time Td - 1 1 3 1 1 1 - - - - SG5: f = 90kHz *2 TMin - 1 1 3 1 1 1 - - - - SG5: f = 90kHz *2 Input high level voltage VIH - 1 1 3 1 1 1 - - - - SG5: f = 90kHz *2 Input low level voltage VIL - 1 1 3 1 1 1 - - - - SG5: f = 90kHz *2 Input high level current IIH - 1 1 2 1 1 1 - - - - - Input low level current IIL - 1 1 1 1 1 1 - - - - - Tdl - 1 2 3 1 1 1 - - - - SG5: f = 90kHz, Vs4 = 9V *2 Output high level HOS - 1 1 3 1 1 1 - - - - SG5: f = 90kHz *2 Output low level LOS - 1 1 3 1 1 1 - - - - SG5: f = 90kHz *2 Output level f characteristic fsaw - 1 1 3 1 1 1 - - - - SG5: f = 30kHz Min. pulse width <HD input pin> <Monostable multivibrator> Delay time <SAW GEN> *3 <Reference voltage supply> Output voltage VREF9 - 1 1 1 1 1 1 - - - - Max. output current Irmax9 - 1 1 1 2 1 1 - - - - Is = – 10mA 1 1 1 1 1 1 - - - - Ta = 0˚C→ 75 ˚C 1 1 1 1 1 1 - - - - Ta = 75˚C Output voltage thermal characteristic Thermal shutdown TREF9 Tdow - - *4 *1 The pin 12 output amplitude should be set to VO. AV = 20log (VO / VIN) [dB] *2 For the method by which the output waveform is determined, refer to Fig. 14. *3 An input frequency should be measured that produces a level of -1dB for a high output level (HOS) for the sawtooth waveform at an input frequency of 30kHz. *4 The temperature is measured at the point where the temperature is raised to above Ta = 75˚C and the output level of pin 9 is high. BA9756FS Multimedia ICs !Application example Hd in 10kΩ 220µF 10 9 GND N.C. + 1500pF 220pF 8 7 6 5 4 N.C. REF 9.0V + 3 2 SAW GEN. – + + + – N.C. 12 13 14 1 N.C. M/M Buffer 11 1µF 15 16 N.C. N.C. 17 18 VCC 19 20 15V 15V + + + +B HRC FBT Anode Voltage Hd pulse Note: N.C. pin processing In order to boost the thermal effect of the IC, we recommend connecting this to the GND or to an adjacent pin. Fig.13 BA9756FS Multimedia ICs Input / output waveforms 3.0V SG5 (Hd IN) 1.5V HOS (SAW OUT) LOS 100% 90% 50% (PWM OUT) 10% 0% Td Tdl TMin. Fig.14 !External dimensions (Units: mm) BA9756FS 1 10 5.4 ± 0.2 11 0.8 0.15 ± 0.1 1.8 ± 0.1 0.11 7.8 ± 0.3 8.7 ± 0.2 20 0.36 ± 0.1 0.3Min. 0.15 SSOP-A20 Tr