TDA8385 Philips Semiconductors, TDA8385 Datasheet
TDA8385
Available stocks
Related parts for TDA8385
TDA8385 Summary of contents
Page 1
... Regulation-indicator output Programmable minimum on-time of switching transistor Accurate peak-current setting. PACKAGE PIN POSITION MATERIAL DIL plastic 2 Preliminary specification TDA8385 GENERAL DESCRIPTION The TDA8385 is intended to be used in combination with the opto-coupler (CNR50 control unit for a self-oscillating power supply. CODE SOT38WBE ...
Page 2
... V ref SUPPLY REFERENCES REGULATION X INDICATOR DIFFERENTIAL AMPLIFIER V ref (2.5 V) CLAMP TCG (min) reset (28) 3 Preliminary specification TDA8385 GND 14 latch V P (min) DETECTOR reset 28 (28, 27, 23 diff TCG MINIMUM VOLTAGE CLAMP 6 CONTROL PART ...
Page 3
... LED CONTROL demagnetization I sim 0 DELAY 12 10 SAWTOOTH GENERATOR (17) (28 Preliminary specification TDA8385 TDA8385 LED 2 LED driver output (23 current simulation input peak-current setting input I peak DEM 15 demagnetization input ...
Page 4
... March 1994 DESCRIPTION cross-referenced in the following description. Supply references (Block I) The TDA8385 is intended to be used on the secondary side of the self-oscillating power supply. It can be supplied either by an auxiliary winding of the transformer or an external supply e. transformer. Charging of the capacitor C ...
Page 5
... March 1994 latch initialization 5.2 7.5 Fig.4 Latch initialization as a function of supply voltage V R12 off Fig.5 Determination of the peak current I 6 Preliminary specification TDA8385 operation (V) MCD403 . P I sim sw1 t MCD404 . c ...
Page 6
... V . TCG (4), ( diff Fig.6 Reference voltage ( function of feedback voltage ( Preliminary specification TDA8385 Control part (Block III) The differential amplifier, sub-section 3, compares the feedback voltage (V ) with the fb reference voltage V . The output of ref the differential amplifier is available on pin 11 to allow gain setting. The ...
Page 7
... This input can be used for feed forward information. mv Fig.8 Characteristics of the control part. 8 Preliminary specification TDA8385 The voltage V determines the Ton(min) minimum on-time of the switching transistor. This voltage can be determined externally with a resistor on pin 4. With this resistor the current ...
Page 8
... VIII) The operation of the over voltage protection circuit is, in the event of the IC being SOPS-supplied, quite different from when the IC is externally supplied. 9 Preliminary specification TDA8385 O IC PERATION WHEN THE IS EXTERNALLY SUPPLIED When the voltage on pin 8 exceeds 2.5 V the slow-start capacitor is slowly discharged ...
Page 9
... (1) For detail see Fig. FF23 Fig.10 Detailed over voltage protection of Fig.9. March 1994 (1) Fig.9 Over voltage protection. t delay slow discharge quick discharge 10 Preliminary specification TDA8385 t t MCD408 7 MCD409 ...
Page 10
... LED driver is released again if the voltage is below 2 V (see Fig.11). handbook, full pagewidth V sb (V) output sub-section 25 I LED (mA) March 1994 is supplied from the SOPS via thyristor TH1 (see Fig.16). In the stand-by state Fig.11 Stand-by operation; burst mode. 11 Preliminary specification TDA8385 2 MCD410 ...
Page 11
... The output of this block is LOW during the regulation mode (V handbook, full pagewidth V 2 diff 0 V RIO 0 A desired delay at power-on reset can be made externally. March 1994 V diff RIO : open-collector output t MCD411 Fig.12 Regulation indicator output; pin 1. 12 Preliminary specification TDA8385 ; see Fig.12). ...
Page 12
... Temperatures T operating ambient temperature amb T storage temperature stg Power dissipation P total power dissipation tot THERMAL RESISTANCE SYMBOL R from junction to ambient in free air th j-a March 1994 CONDITIONS pin 2 connected pin 2 open-circuit PARAMETER 13 Preliminary specification TDA8385 MIN. MAX. UNIT 0 0 0.5 + 0.5 +3.9 V 0.1 +0.5 V 0.5 +0 ...
Page 13
... V = 1 2. note 2 note 0 0 Preliminary specification TDA8385 TYP. MAX. UNIT 20 V 7 0.58 V 2 kHz 6 1 300 diff os 0.27 V 0.6 V ...
Page 14
... 100 mA 0 see Fig.15; pin 6 not connected see Fig. 115 Preliminary specification TDA8385 TYP. MAX. UNIT 300 mV 6 0.21 1.1 V 300 mV 200 mV 140 mV 500 ...
Page 15
... I = 250 A 3 2.4 450 Preliminary specification TDA8385 TYP. MAX. UNIT 1.2 1 100 mV 1 ns/pF 2.5 2.6 V 500 550 2.5 2 140 mV 0 ...
Page 16
... R = 2.7 k ref 4 see Fig. see Fig.14 diff March 1994 V diff (pin 11 MCD412 Frequency = 50 kHz. Slew rate = 0.2 s. Fig.14 Supply voltage ripple rejection; STATUS 17 Preliminary specification TDA8385 ~ ~ 3 V MCD413 function of time. diff ...
Page 17
... Philips Semiconductors Control circuit for a Self-Oscillating Power Supply (SOPS) handbook, full pagewidth demagnetization input (pin 15) peak-current setting input (pin 5) Fig.15 Timing diagram; demagnetization delay time. March 1994 115 mV 90% 10% t demLH t demHL 18 Preliminary specification TDA8385 ~ ~ + 0 – 0 MCD414 ...
Page 18
... Philips Semiconductors Control circuit for a Self-Oscillating Power Supply (SOPS) APPLICATION INFORMATION March 1994 Preliminary specification 19 TDA8385 pagewidth full handbook, ...
Page 19
... DEMAGNETIZATION output sub-section 14 LED driver March 1994 storage time and delay RESET (sub-section 13) delay V r (output sub-section 7) comparator (18) level = 1 V (output sub-section 10) SET (sub-section 13) Fig.17 Application timing diagram. 20 Preliminary specification TDA8385 T off (SOPS) t MCD416 ...
Page 20
... Control circuit for a Self-Oscillating Power Supply (SOPS) PACKAGE OUTLINE 3.9 3.4 2.2 max 16 1 Dimensions in mm. Fig.18 16-lead dual in-line; plastic with internal heat spreader; opposite bent leads (SOT38WBE). March 1994 22.00 21.35 5.1 max 1.2 min 2.54 0.254 M 0.53 (14x) max 1.4 max 9 6.48 6. Preliminary specification TDA8385 8.25 7.80 0.32 max 7.62 9.5 8.3 MSA349 ...
Page 21
... Preliminary specification TDA8385 R EPAIRING SOLDERED JOINTS Apply a low voltage soldering iron below the seating plane (or not more than 2 mm above it). If its temperature is below 300 C, it must not be in contact for more than 10 s ...