ZXSC400 Zetex Semiconductors plc., ZXSC400 Datasheet
ZXSC400
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ZXSC400 Summary of contents
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... LED DRIVER BOOST CONVERTER DESCRIPTION The ZXSC400 is a voltage mode boost converter in the SOT23-6 package. Its low feedback voltage allows the current in a chain of LEDs to be set and accurately monitored with a single resistor giving minimal losses. Its excellent load and line regulation means that for the full supply range from lithium-ion cells, the LED current will typically change by less than 1% ...
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... ZXSC400 ABSOLUTE MAXIMUM RATINGS V -0.3V to +10V CC DRIVE -0. EOR -0. STDN -0.3V to The lower of (+5.0V SENSE -0.3V to The lower of (+5.0V Operating Temp. -40°C to +85°C Storage Temp. -55°C to +125°C Power Dissipation 450mW ELECTRICAL CHARACTERISTICS Test Conditions V = 3V unless otherwise stated. ...
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... TYPICAL CHARACTERISTICS ISSUE 1 - JANUARY 2003 3 ZXSC400 ...
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... ZXSC400 DESIGN INFORMATION IC operation 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. Dynamic Drive Output Depending on the input signal, the output is either “LOW” or “HIGH”. In the high state a 2.5mA current source (max drive voltage = V -0 ...
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... Inductor selection has a significant impact on the converter performance. For applications where efficiency is critical, an inductor with a series resistance of 250m or less should be used. A list of recommended inductors is listed in the table below ZXSC400 I ( 0.5 0.457 0.4 0.676 1.0 0.24 0.6 0.1 ...
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... ZXSC400 is enabled and the driver is in normal operation. When the voltage at the STDN pin is 0.7V or lower, the ZXSC400 is disabled and the driver is in shutdown mode. The SHDN input is a high impedance current source typ. The driving device can be an open collector or an open drain or a logic output with a “ ...
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... PWM waveform on this pin and varying the duty cycle, LED current and hence LED brightness can be adjusted. To implement this method of brightness control on the ZXSC400, apply PWM signal with amplitude of between 0.7V and Vcc at a frequency of 120Hz or above (to eliminate LED flicker). The LED current and hence ...
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... LED current that will be added to the minimum LED current. The formula for selecting values for R1 and R2 are given below: LOGIC SIGNAL R1 MOSFET ‘off’ LED(MIN) R LEB MOSFET ‘on’ V FLB I LED(MAX) R LEB Where V = 300mV 10k R1 8 ZXSC400 LED(MIN) ISSUE 1 - JANUARY 2003 ...
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... To optimise for best performance each of these loops kept separate from each other and interconnected with short, thick traces thus minimising parasitic inductance, capacitance and resistance. Also the R resistor should be connected, with minimum SENSE trace length, between emitter lead of Q1 and ground, again minimising stray parasitics. 9 ZXSC400 ...
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... REFERENCE DESIGNS Li - Ion to 2 LED converter 100 2 White LEDs I =20mA LED 2.5 3.0 Input voltage (V) Input Voltage vs Efficiency Bill of Materials Ref Value Part Number U1 ZXSC400 U2 ZX3CDBS1M832 CMD4D11-100MC R1 100m LR1206 / RL1220 R2 15 Generic C1 2.2 F/6V3 GRM Series C2 2.2 F/16V GRM Series LED NSCW215 ...
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... White LEDs 3.5 4.0 2.5 Input Voltage v LED Current Manufacture Zetex Zetex Sumida IRC / Cyntec Generic Murata Murata Nichia 11 ZXSC400 3.0 3.5 4.0 Input Voltage (V) Comments LED driver IC NPN + Schottky dual 1mm height profile 1206 / 0805 size 0603 size 0805 size 1206 size White SMT LED ...
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... ZXSC400 Li - Ion to 4 LED converter 90 4 White LEDs I =20mA LED 2.5 3.0 Input voltage (V) Input Voltage vs Efficiency Bill of Materials Ref Value Part Number U1 ZXSC400 U2 ZX3CDBS1M832 CMD4D11-100MC R1 47m LR1206 / RL1220 R2 15 Generic C1 2.2 F/6V3 GRM Series C2 2.2 F/16V GRM Series LED NSCW215 30 4 White LEDs ...
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... Input Voltage (V) Input Voltage vs LED Current Manufacture Zetex Zetex Zetex Sumida IRC / Cyntec Generic Murata Murata Nichia 13 ZXSC400 3.5 4.0 Comments LED driver IC 40V NPN 1A Schottky diode 1mm height profile 1206 / 0805 size 0603 size 0805 size 1206 size White SMT LED ...
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... ZXSC400 Li - Ion to 8 LED converter 90 8 White LEDs I =20mA LED 2.5 3.0 Input voltage (V) Input Voltage vs Efficiency Bill of Materials Ref Value Part Number U1 ZXSC400 Q1 FMMT619 D1 ZHCS1000 CDRH4D28-220 or D01608C-223 R1 33m LR1206 / RL1220 R2 15 Generic C1 2.2 F/6V3 GRM Series C2 2.2 F/35V GRM Series LED NSCW215 ...
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... Notes ISSUE 1 - JANUARY 2003 15 ZXSC400 ...
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... ZXSC400 PACKAGE OUTLINE CONTROLLING DIMENSIONS IN MILLIMETRES APPROX CONVERSIONS INCHES. PACKAGE DIMENSIONS Millimetres DIM Min Max A 0.90 1.45 A1 0.00 0.15 A2 0.90 1.30 b 0.35 0.50 C 0.09 0.20 D 2.80 3.00 © Zetex plc 2003 Europe Zetex plc Zetex GmbH Fields New Road Streitfeldstraße 19 Chadderton D-81673 München Oldham, OL9 8NP ...