ZXSC440 Zetex Semiconductors plc., ZXSC440 Datasheet
ZXSC440
Available stocks
Related parts for ZXSC440
ZXSC440 Summary of contents
Page 1
... PHOTOFLASH CHARGER DESCRIPTION The ZXSC440 is a dedicated photoflash charger, charging photoflash capacitor to 300V in 3.5 seconds from a 3V supply. The flyback conversion efficiency is typically 75%, much higher than the commonly used discrete charging circuits. The Charge pin enables the circuit to be initiated from the camera's microprocessor, using negligible current when flash is not being used ...
Page 2
... ZXSC440 ABSOLUTE MAXIMUM RATINGS PARAMETER V CC DRIVE READY CHARGE V , SENSE FB Operating temperature Storage temperature Power dissipation at 25°C ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER V V range CC CC (1) Iq Quiescent current I Shutdown current STDN (2) Eff Efficiency Acc Reference tolerance REF TCO Reference temp co REF ...
Page 3
... Inductor current sense input. Internal threshold voltage set to 28mV. Connect external sense resistor 4 N/C 5 CHARGE Initiate photoflash capacitor charging 6 READY Signal to microprocessor when photoflash capacitor charged 7 GND Ground 8 V Supply voltage, 1. BLOCK DIAGRAM ISSUE 1 - JANUARY 2005 ZXSC440 ...
Page 4
... ZXSC440 DEVICE DESCRIPTION Bandgap reference All threshold voltages and internal currents are derived from a temperature compensated bandgap reference circuit with a reference voltage of 1.22V nominal. If the REF terminal is used as a reference for external devices, the maximum load should not exceed ±2 A. Dynamic drive output Depending on the input signal, the output is either " ...
Page 5
... TYPICAL OPERATING CHARACTERISTICS (For typical application circuit at V ISSUE 1 - JANUARY 2005 =3V and T =25 °C unless otherwise stated ZXSC440 ...
Page 6
... ZXSC440 APPLICATIONS Switching transistor selection The choice of switching transistor has a major impact on the converter efficiency. For optimum performance, a bipolar transistor with low V CE(SAT) required. The V of the switching transistor is also an CEO important parameter as this sees typically three times the input voltage when the transistor is switched off. ...
Page 7
... Amp. Turns and small cores will need an air gap to cope with this value without saturation. Secondary winding capacitance should not be too high as this is working at 300V and could soon cause excessive losses. ZXSC440 Transformer specifications Part No. Size L PRI (WxLxH) mm ...
Page 8
... Output voltage adjustment The ZXSC440 are adjustable output converters allowing the end user the maximum flexibility. For adjustable operation a potential divider network is connected as follows ...
Page 9
... Also the R resistor should be connected, with minimum SENSE trace length, between emitter lead of Q1 and ground, again minimizing stray parasitics. and to SENSE 9 ZXSC440 ...
Page 10
... Two BAS21 200V rectifier diodes are connected in series and used in place of a 400V rectifier diode to provide faster switching speeds and higher efficiency Circuit diagram Part number Manufacturer Notes ZXSC440 Zetex ZXMN6A07F Zetex 60V N-channel MOSFET BAS21 Philips ...
Page 11
... See note RL1210 Cyntec Generic Generic Generic Generic Generic Generic Output voltage across resistor Generic Generic Generic Murata GRM Series Murata Generic Generic Output voltage seen across capacitor Generic Generic FW Series Rubycon Photoflash capacitor 11 ZXSC440 ( ...
Page 12
... C5 80uF/330V Radial NOTES: (1) Transformer specification: Primary inductance: 32uH, Core: Sumida CEEH64, Turns ratio: 1: Circuit diagram Part number Manufacturer Notes ZXSC440 Zetex ZXTD6717 Zetex NPN/PNP dual FMMT619 Zetex 50V NPN low sat BAS21 Philips 200V fast rectifier ...
Page 13
... NOTES: ISSUE 1 - JANUARY 2005 13 ZXSC440 ...
Page 14
... ZXSC440 NOTES ISSUE 1 - JANUARY 2005 14 ...
Page 15
... NOTES: ISSUE 1 - JANUARY 2005 15 ZXSC440 ...
Page 16
... ZXSC440 PACKAGE OUTLINE 8 1 INDENT AREA (D/2 X E1/2) Controlling dimensions are in millimeters. Approximate conversions are given in inches PACKAGE DIMENSIONS Millimeters Inches DIM Min Max Min Max A - 1.10 - 0.0433 A1 0.05 0.15 0.002 0.006 A2 0.75 0.95 0.0295 0.0374 b 0.25 0.40 0.010 0.0157 c 0.13 0.23 0.005 0.009 D 2.90 3.10 0.114 0.122 © Zetex Semiconductors plc 2005 Europe ...