AN_SY7201 Rev0.3

AN_SY7201 Rev. 0.3
Silergy Corp. Confidential- Prepared for Customer Use Only
2
AN_SY7201
Electrical Characteristics
(VIN = 3.6V, TA = 25°C, unless otherwise specified)
Parameter Input Voltage Range Quiescent Current Shutdown Current Feedback Reference Voltage FB Input Current Low Side Main FET RON Main FET Current Limit EN Rising Threshold EN Falling Threshold Input UVLO Threshold UVLO Hysteresis Oscillator Frequency Min On Time Max Duty Cycle Thermal Shutdown Thermal Hysteresis Output Clamp voltage
Recommended Operating Conditions (Note 3)
IN, ------------------------------------------------------------------------------------------------------------------- 2.5V to 30V LX, OVP ----------------------------------------------------------------------------------------------------------- 2.5V to 30V All other pins ------------------------------------------------------------------------------------------------------ 0 to 3.6V Junction Temperature Range ------------------------------------------------------------------------------------ -40°C to 125°C Ambient Temperature Range ----------------------------------------------------------------------------------- -40°C to 85°C
Absolute Maximum Ratings (Note 1)
IN, ------------------------------------------------------------------------------------------------------------------- 32V LX, OVP ---------------------------------------------------------------------------------------------------------- 36V All other pins ------------------------------------------------------------------------------------------------------- 6V Power Dissipation, PD @ TA = 25°C, SOT23-6 --------------------------------------------------------------- 0.4W Package Thermal Resistance (Note 2) SOT23-6, θJA -------------------------------------------------------------------------------------------- 250°C/W SOT23-6, θJC -------------------------------------------------------------------------------------------- 130°C/W Junction Temperature Range ------------------------------------------------------------------------------------ 150°C Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------- 260°C Storage Temperature Range ------------------------------------------------------------------------------------- -65°C to 150°C ESD Susceptibility (Note 2) HBM (Human Body Mode) ------------------------------------------------------------------------------------- 2kV MM (Machine Mode) -------------------------------------------------------------------------------------------- 200V
R1
Figure 1. Schematic Diagram
AN_SY7201 Rev. 0.3
Silergy Corp. Confidential- Prepared for Customer Use Only
1
AN_SY7201
Pinout (top view)
LX 1 6 IN
GND
2
5
OVP
Ordering Information
SY7201□(□□)□ Temperature Code Package Code Optional Spec Code
Applications
• GPS Navigation Systems • Handheld Devices • Portable Media Players
AN_SY7201
30V High Current Boost LED Driver Preliminary Specification General Description
SY7201 is a DC/DC step-up converter that delivers an accurate constant current for driving LEDs. Operation at a fixed switching frequency of 1MHz allows the device to be used with small value external ceramic capacitors and inductor. LEDs connected in series are driven with a regulated current set by the external resistor. The SY7201 is ideal for driving up to eight white LEDs in series or up to 30V.
Temperature Range: -40°C to 85°C Ordering Number SY7201ABC Package type SOT23-6 Note 2A
Typical Applications
L Vin Cin
Dimming IN EN/PWM GND LX OVP FB
D Vout Cout
Features
• • • • • • • • Input voltage range 2.5V to 30V Switch current limit 2A Drives LED strings up to 30V 1MHz fixed frequency minimizes the external components Internal softstart limits the inrush current Open LED overvoltage protection RoHS Compliant and Halogen Free Compact package: SOT23-6 pin
Symbol VIN IQ ISHDN VREF IFB RDS(ON) ILIM VENH VENL VUVLO VHYS FOSC TSD THYST VOCL
Conditions VFB=0.3V EN=0
Min 2.5
Typ 0.1 10 200 200
196 VFB=0.3V 2 1.5
Max 30 0.6 15 204 1FB3 Nhomakorabea4
EN/PWM
(SOT23-6) Top Mark: DQxyz (Device code: DQ, x=year code, y=week code, z= lot number code) Pin Name LX GND FB EN/PWM OVP IN Pin Number 1 2 3 4 5 6 Pin Description Inductor node. Connect an inductor between IN pin and LX pin. Ground pin. Feedback pin. Connect a resistor R1 between FB and GND to program the output current: IOUT=0.2V/R1. Enable and dimming control. The recommended PWM frequency should be higher than 20kHz. Over voltage protection. The value is 33V. Input pin. Decouple this pin to GND pin with 1uF ceramic capacitor.