lt3502aidc-trpbf Linear Technology Corporation, lt3502aidc-trpbf Datasheet
lt3502aidc-trpbf
Related parts for lt3502aidc-trpbf
lt3502aidc-trpbf Summary of contents
Page 1
... DA current sense provides further protection in fault conditions. An internal boost diode reduces com- ponent count LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners 0.1μ ...
Page 2
... LT3502AEDC#PBF LT3502AEDC#TRPBF LT3502AIDC#PBF LT3502AIDC#TRPBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi label on the shipping container. Consult LTC Marketing for information on non-standard lead based fi nish parts. For more information on lead free part marking, go to: For more information on tape and reel specifi ...
Page 3
... SHDN SHDN with statistical process controls. The LT3502IDC and LT3502AIDC are guaranteed over the – 40°C to 125°C operating junction temperature range. Note 3: Current limit guaranteed by design and/or correlation to static test. Slope compensation reduces current limit at higher duty cycle. ...
Page 4
LT3502/LT3502A TYPICAL PERFORMANCE CHARACTERISTICS LT3502 5V Effi ciency OUT 100 12V 24V 0.1 0.2 0.3 0.4 0.5 LOAD CURRENT (A) 3502 G04 LT3502 Maximum Load Current V ...
Page 5
TYPICAL PERFORMANCE CHARACTERISTICS SHDN Pin Current 300 250 200 150 100 SHDN PIN VOLTAGE (V) 3502 G13 LT3502A Maximum V for Full IN Frequency (V = 3.3V) OUT ...
Page 6
LT3502/LT3502A TYPICAL PERFORMANCE CHARACTERISTICS LT3502 Typical Minimum Input Voltage (V = 5V) OUT 0.001 0.01 0.1 LOAD CURRENT (A) 3502 G22 PIN FUNCTIONS V (Pin 1): The V pin supplies current ...
Page 7
BLOCK DIAGRAM INT REG AND UVLO ON OFF SLOPE R3 COMP SHDN 4 C4 OSC FREQUENCY FOLDBACK OPERATION The LT3502/LT3502A are constant frequency, current mode step-down regulators. An oscillator enables an RS fl ip-fl ...
Page 8
LT3502/LT3502A APPLICATIONS INFORMATION FB Resistor Network The output voltage is programmed with a resistor divider between the output and the FB pin. Choose the 1% resis- tors according to: V OUT R1= R2 – 1 0.8V R2 should be 20k ...
Page 9
APPLICATIONS INFORMATION V SW 20V/DIV I L 500mA/DIV V OUT 100mV/DIV V = 40V 1μs/DIV 3.3V OUT L = 6.8μ 10μF OUT I = 250mA OUT Figure 2. Pulse Skip Occurs when Required On Time ...
Page 10
LT3502/LT3502A APPLICATIONS INFORMATION There are several graphs in the Typical Performance Characteristics section of this data sheet that show the maximum load current as a function of input voltage and inductor value for several popular output voltages. Low inductance may ...
Page 11
APPLICATIONS INFORMATION Figure 4 shows the transient response of the LT3502A with several output capacitor choices. The output is 3.3V. The load current is stepped from 150mA to 400mA and back to Table 2 VENDOR PHONE Panasonic (714) 373-7366 Kemet ...
Page 12
LT3502/LT3502A APPLICATIONS INFORMATION drop) resulting from a larger output capacitor and a phase lead capacitor. The last photo shows the response to a high performance electrolytic capacitor. Transient performance is improved due to the large output capacitance. BOOST Pin Considerations ...
Page 13
APPLICATIONS INFORMATION START 4 RUN 0.001 0.01 0.1 LOAD CURRENT (A) (6a) LT3502A Typical Minimum Input Voltage START RUN 0.001 0.01 0.1 LOAD CURRENT ...
Page 14
LT3502/LT3502A APPLICATIONS INFORMATION SHDN RUN GND RUN 50k SHDN 0.1μF GND Figure 7. To Soft Start the LT3502A, Add a Resistor and Capacitor to the SHDN Pin V SW 10V/DIV I L 500mA/DIV V = 40V 2μs/DIV ...
Page 15
APPLICATIONS INFORMATION current peaks at 20A. One method of damping the tank circuit is to add another capacitor with a series resistor to the circuit. In Figure 9b an aluminum electrolytic capacitor has been added. This capacitor’s high equivalent series ...
Page 16
LT3502/LT3502A APPLICATIONS INFORMATION voltage overshoot (it also reduces the peak input current). A 0.1μF capacitor improves high frequency fi ltering. This solution is smaller and less expensive than the electrolytic capacitor. For high input voltages its impact on effi ciency ...
Page 17
APPLICATIONS INFORMATION High Temperature Considerations The die temperature of the LT3502/LT3502A must be lower than the maximum rating of 125°C. This is generally not a concern unless the ambient temperature is above 85°C. For higher temperatures, care should be taken ...
Page 18
LT3502/LT3502A TYPICAL APPLICATIONS 0.1μ BOOST 40V C2 1μF SW LT3502A DA SHDN FB OFF ON GND C1: JMK212BJ226MG L1: LQH43CN4R7M03 0.1μ ...
Page 19
... NOTE 6) 0.200 REF Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. DC Package 8-Lead Plastic DFN (2mm × 2mm) (Reference LTC DWG # 05-08-1719 Rev Ø ...
Page 20
... High Effi ciency Step-Down OUT DC/DC Converter LTC3548 Dual 400mA + 800mA, 2.25MHz Synchronous Step-Down DC/DC Converter Burst Mode is a registered trademark of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. Linear Technology Corporation 20 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● ...