View TDA7256_267717.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

(R)
TDA7256
30W BRIDGE CAR RADIO AMPLIFIER
NO AUDIBLE POP DURING MUTE AND STANDBY OPERATIONS MUTING TTL COMPATIBLE VERY LOW STANDBY CONSUMPTION PROGRAMMABLE TURN ON DELAY DIFFERENTIAL INPUT SHORT CIRCUIT PROTECTIONS: RL SHORT - OUT TO GROUND - OUT TO VS OTHER PROTECTIONS: - Load dump voltage surge - Loudspeaker DC current - Very inductive load - Overrating temperature - Open ground DESCRIPTION The TDA7256 is a class AB fully protected bridge power amplifier, designed for car radio applicaBLOCK DIAGRAM
MULTIWATT11 ORDERING NUMBER: TDA7256
tions. The high current capability allows to drive low impedance loads (up to 2). The differential inputs availability makes it particularly suitable for boosters and active loudspeakers applications.
October 1998
1/10
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
TDA7256
PIN CONNECTION (Top view)
ABSOLUTE MAXIMUM RATINGS
Symbol VS VS VS Io Io Ptot Tstg, TJ Operating Supply Voltage DC Supply Voltage Peak Supply Voltage (for 50ms) Output Peak Current (non repetiitive t = 0.1ms) Output Peak Current Repetitive f > 10Hz Power Dissipation (Tcase = 85C) Storage and Junction Temperature Range Parameter Test Conditions 18 28 40 internally limited 5.5 36 -40 to +150 A W C Unit V V V
THERMAL DATA
Symbol Rth j-case Description Thermal Resistance Junction-case Max Value 1.8 Unit C/W
2/10
TDA7256
ELECTRICAL CHARACTERISTICS (VS = 14.4V, RL = 4, f = 1KHz; Tamb = 25C, unless otherwise specified)
Symbol VS Iq Ri CMR VOS Po Parameter Supply Voltage Quiescent Drain Current Input Resistance Common Mode Rejection Output Offset Voltage Output Power d = 10% R L = 4 R L = 3.2 R L = 2 Po = 0.1W to 13W R g = 10K, B = 22Hz to 22KHz R g = 10K, Vr = 1Vrms, f = 300Hz Vref = 1Vrms, f = 100Hz to 10KHz Pin 1 Pin 1 Vref = 1Vrms 60 100 145 45 60 2.4 0.8 18 22 26 30 0.05 36 3 60 10 0.5 f = 1KHz, Vin = 100mV 50 60 150 Test Condition Min. 8 80 Typ. Max. 18 150 Unit V mA K dB mV W W W % dB V dB dB V V dB A C
d GV eN SVR
Distortion Voltage Gain (CL) Total Input Noise Voltage Supply Voltage Rejection Muting Attenuation Muting-in Threshold Voltage Muting-out Threshold Voltage Stand-by Attenuation Stand-by Current Consumption
TSD
Thermal Shut-down Junction Temperature
Figure 1: Test and Application Circuit
3/10
TDA7256
Figure 2: P.C. and Layout of the fig.1 (1:1 scale)
Figure 3: Drain Current vs. Supply Voltage
Figure 4: Output Power vs. Supply Voltage
4/10
TDA7256
Figure 5: Output Power vs. Supply Voltage Figure 6: Output Power vs. Supply Voltage
Figure 7: Distortion vs. Output Power
Figure 8: Distortion vs. Output Power
Figure 9: Distortion vs. Output Power
Figure 10: Distortion vs. Frequency
5/10
TDA7256
Figure 11: Distortion vs. Frequency Figure 12: SVR vs. Frequency
Figure 13: CMRR vs. Frequency
Figure 14: Power Dissipation & Efficiency vs. Output Power
Figure 15: Power Dissipation & Efficiency vs. Output Power
Figure 16: Power Dissipation & Efficiency vs. Output Power
6/10
TDA7256
CIRCUIT DESCRIPTION INPUT STAGE The input stage is a differential type preamplifier stage with two independent inputs and two outputs in phase opposition. It is designed for particular linearity characteristics in order to have output amplitude large enough (1VPP) yet maintaining low distortion. The voltage gain of the stage is 6 dB.The possibility to use the differential input allows the system immunity to common-mode noise in case of long wire connections (fig. 17 ) Figure 17: Balanced -Unbalanced Input TURN-ON The TDA7256 is fully popless at turn-on thanks to a delay circuit which keeps the output low during the capacitors charge transient. The delay-time is given by the following formula: To = 800 C10 + 600 (C9 + C11) ( C10 + 1) C9 + C11
TURN-OFF The ground compatible structures and the choice of a soft turn-off circuit ensure a fully popless operation. OUTPUT STAGE It is a power stage designed in a way of being able to drive loads up to 2 ohm in bridge configuration without bootstrap capacitors (22 W with RL=4 ohm , 30W with RL=2 ohm). SVR The noises coming from the car environment are essentially inside the bandwith from 300 Hz to 6 KHz. The ripple rejection circuit which utilizes also the gain capacitors C11,C9 ensures in this frequency range a rejection typ. of 60dB. SHORT CIRCUIT PROTECTION The short circuit protection circuits intervene in the following cases: - s.c. between one output and ground - s.c. between one output and +Vs - s.c. between the outputs In the first two cases they stop the current in both the final stages,allowing also loudspeaker protection.In the last case the current is limited, thus avoiding the load point to reach the SOA of the output transistors. STAND-BY In stand-by condition the current generators are disabled:the current drops to a very low value (few A). Also this function is fully popless. Fig. 19 shows the silent transients of turn-on and turn-off operations through both the mute and the stand-by pins.
MUTE The mute circuit (TTL compatible) acts at preamplifier level and disables the inputs without changing the DC voltage values. In such a way the operation is fully popless.The use of a RC network produces a soft reduction of the audio signal providing the best effect from the acoustic point of view (fig 18). The mute circuit is also activated during turnon/turn-off operations when the voltage at standby pin is lower than about 2 volt Figure 18: Soft Muting
7/10
TDA7256
Figure 19: Silent Transients Through the Mute and Stand-by pins.
8/10
TDA7256
mm MIN. TYP. MAX. 5 2.65 1.6 1 0.49 0.88 1.45 16.75 19.6 20.2 21.9 21.7 17.4 17.25 10.3 2.65 4.25 4.73 1.9 1.9 3.65 22.2 22.1 17.5 10.7 4.55 5.08 22.5 22.5 18.1 17.75 10.9 2.9 4.85 5.43 2.6 2.6 3.85 0.862 0.854 0.685 0.679 0.406 0.104 0.167 0.186 0.075 0.075 0.144 0.874 0.87 0.689 0.421 0.179 0.200 1.7 17 0.55 0.95 1.95 17.25 0.019 0.035 0.057 0.659 0.772 0.795 0.886 0.886 0.713 0.699 0.429 0.114 0.191 0.214 0.102 0.102 0.152 0.067 0.669 0.039 0.022 0.037 0.077 0.679 MIN. inch TYP. MAX. 0.197 0.104 0.063
DIM. A B C D E F G G1 H1 H2 L L1 L2 L3 L4 L7 M M1 S S1 Dia1
OUTLINE AND MECHANICAL DATA
Multiwatt11 V
9/10
TDA7256
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. (c) 1995 SGS-THOMSON Microelectronics - All Rights Reserved MULTIWATT (R) is a Registered Trademark of SGS-THOMSON Microelectronics SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A.
10/10

▲Up To Search▲

Price & Availability of TDA7256

	To Download TDA7256 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .