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Details, datasheet, quote on part number:ZXSC300
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Datasheet text preview:
ZXSC300
SINGLE OR MULTI CELL LED DRIVER SOLUTION
DESCRIPTION The ZXSC300 is a single or multi cell LED driver designed for applications where step-up voltage conversion from very low input voltages is required. These applications mainly operate from single 1.5V or 1.2V battery cells. The circuit generates constant current pulses that are ideal for driving single or multiple LED's over a wide range of operating voltages. The ZXSC300 is a PFM controller IC that drives an external Zetex switching transistor with a very low saturation resistance. These transistors are the best switching devices available for this type of switching conversion enabling high efficiency conversion with input voltages below 1 volt. The drive output of the ZXSC controller generates a dynamic drive signal for the switching transistor. The circuit can start up under full load and operates down to an input voltage of 0.8 volts. The solution configuration ensures optimum efficiency over a wide range of load currents, several circuit configurations are possible depending on battery life versus brightness considerations. The ZXSC300 is offered in the SOT23-5 package which, when combined with a SOT23 switching transistor, generates a high efficiency small size circuit solution. The IC and discrete combination offers the ultimate cost vs performance solution for single cell LED driving applications.
FEATURES · · · · · 94% efficiency Minimum operating input voltage 0.8V Fixed output current Low saturation voltage switching transistor SOT23-5 package ORDERING INFORMATION DEVICE ZXSC300E5 Package SOT23-5 Partmarking C300
TYPICAL APPLICATION CIRCUIT
VBATT
L1
100µH
U1
Vcc V drive Isense Gnd ZXSC300
Q1
FMMT617
LED1
WHITE LED
R1
0.33R
ISSUE 1 - JUNE 2001 1
ZXSC300
ABSOLUTE MAXIMUM RATING
Supply Voltage Maximum Voltage Other Pins Power Dissipation -0.3 to 10V -0.3 to VCC+0.3V 450mW Operating Temperature Storage Temperature -40 to 85°C -55 to 125°C
ELECTRICAL CHARACTERISTICS: Test conditions unless otherwise stated: VCC=1.5V, TAMB=25°C
Symbol VCC Parameter Efficiency1 Recommended supply voltage range Minimum startup and operating voltage Quiescent current2 Base drive current Supply current High level drive voltage Low level drive voltage Output current reference voltage ISENSE voltage temp co.2 ISENSE input current VISENSE = 0V 0
3
Conditions
Min 0.8
Typ
Max 94 8
Units % V
VCC(min)
IDRIVE=-600µA, VDRIVE=0.7V IDRIVE=-600µA, VDRIVE=0.7V, TAMB=-10°C3 VDRIVE = 0.7V, VISENSE = 0V VDRIVE = 0.7V, VISENSE = 0V VISENSE = 0V, IVDRIVE =-0.5mA VISENSE = 50mV, IVDRIVE = 5mA 1.5 2 VCC-0.3 0 14
0.8 0.9 0.2
0.92
V
IQ IVDRIVE ICC VVDRIVE(high) VVDRIVE(low) VISENSE (threshold) TCVISENSE IISENSE
mA 3.6 4 VCC 0.2 mA mA V V mV %/°C -65 µA
19 0.4 -30
24
ELECTRICAL CHARACTERISTICS: AC PARAMETERS2 TEST CONDITIONS (Unless otherwise stated) ) VCC=1.5V, TAMB = 0 to 70°C
Symbol TDRV FOSC
1 2
Parameter Discharge Pulse Width Recommended operating frequency4
Conditions
Min 1.2
Typ 1.7
Max 3.2 200
Units µs kHz
Application dependent, see reference designs. These parameters guaranteed by Design 3 Total supply current =IQ + IVDRIVE, see typical characteristics 4 Operating frequency is application circuit dependent. See applications section.
ISSUE 1 - JUNE 2001 2
ZXSC300
FMMT617
For the circuits described in the applications section, Zetex FMMT617 is the recommended pass transistor. The following indicates outline data for the transistor, more detailed information can be found in the Zetex surface mount data book or at www.zetex.com
ELECTRICAL CHARACTERISTICS (at TA = 25°C unless otherwise stated).
PARAMETER Collector-Emitter Saturation Voltage Collector-Emitter Breakdown Voltage SYMBOL MIN. VCE(sat) TYP. 8 70 150 18 MAX. 14 100 200 UNIT mV mV mV V CONDITIONS. IC=0.1A, IB=10mA* IC=1A, IB=10mA* IC=3A, IB=40mA* IC=10mA*
V(BR)CEO 15
*Measured under pulsed conditions. Pulse width=300µs. Duty cycle 2%
ZHCS1000
For the circuits described in the applications section Zetex ZHCS1000 is the recommended Schottky diode. The following indicates outline data for the diode, more detailed information is available at www.zetex.com
ELECTRICAL CHARACTERISTICS (at Tamb = 25°C unless otherwise stated).
PARAMETER Forward Voltage Reverse Current Reverse Recovery Time SYMBOL VF IR trr 50 12 MIN. TYP. MAX. 400 500 100 UNIT mV mV µA ns CONDITIONS. IF=500mA IF=1A VR=30V Switched from IF = 500mA to IR = 500mA. Measured at IR=50mA
ISSUE 1 - JUNE 2001 3
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