AP1538 DIODES [Diodes Incorporated], AP1538 Datasheet
AP1538
Available stocks
Related parts for AP1538
AP1538 Summary of contents
Page 1
... AP1538 Rev. 2 18V 3A 300KHz BUCK CONVERTER General Description AP1538 consists of step-down switching regulator with PWM control. These devices include a reference voltage source, oscillation circuit, error amplifier, internal PMOS. AP1538 provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to vary the duty ratio linearly from 99% ...
Page 2
... Add an external resistor to set max output current power supply pin CC Switch Pin. Connect external inductor/diode here. Minimize trace Output 5, 6 area at this pin to reduce EMI GND Pin SS AP1538 Rev. 2 18V 3A 300KHz BUCK CONVERTER (2) SOP-8L-DEP (Dual Exposed Pads) Vss Vss ...
Page 3
... Operating Ambient Temperature A Notes: 4. For the operations in low input voltage, AP1538 can tolerate down to 3.6V but max output current loading will be less than 3A. For nominal applications in such low input voltage range, especially lower than 4V, a higher ROCSET with larger heat sink is recommended. AP1538 Rev. 2 ...
Page 4
... HYS Thermal Resistance θ JC Junction-to-Case Notes: 5. Test condition for SOP-8L and SOP-8L-DEP: Devices mounted on 2oz copper, minimum recommended pad layout on top & bottom layer with thermal vias, double sided FR-4 PCB. AP1538 Rev. 2 18V 3A 300KHz BUCK CONVERTER Conditions I = 0.1A OUT I = 0.1A OUT ...
Page 5
... C IN 470uF R EN CVcc 100K 0.1uF C EN 0.1uF Notes: 6. Suggested DIODES Power Schottky P/N: B340 series or PDS340. 7. Suggested C for V < 1V; 680μF. OUT OUT 8. Typical feedback compensation (Cc): 5600pF. AP1538 Rev. 2 Vcc Output AP 1538 OCSET FB OCSET OUT 0.7K~5 K ohm ...
Page 6
... V (V) IN Line Regulation (V = 3.3V, I OUT OUT 3.40 3.35 3.30 3.25 3.20 3.15 3.10 3.05 3. Efficiency (V = 12V) IN 100 0.0 1.0 I OUT AP1538 Rev 0.2A) 0.820 0.815 0.810 0.805 0.800 0.795 0.790 0.785 0.780 0.2A) 3.35 3.34 3.33 3.32 3.31 3.30 3.29 3.28 3.27 3.26 3. (V) 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 VOUT=3.3V 3.0 VOUT=5V 2.5 2.0 3.0 ( www ...
Page 7
... Ambient Temperature (C) V Ripple OUT (V = 12V 3.3V OUT Load Transient Response (V = 12V 3.3V OUT AP1538 Rev. 2 18V 3A 300KHz BUCK CONVERTER (Continued) =6.8k 100 = 0.1A) OUT = 0.1~3A) OUT www.diodes.com AP1538 V Ripple OUT (V = 12V 3.3V 3.0A) IN OUT OUT JUNE 2008 © Diodes Incorporated ...
Page 8
... Test Circuit OUTPUT V CC OCSET EN A Enable function test OUTPUT V CC OCSET + EN - Operation function test AP1538 Rev. 2 open open www.diodes.com AP1538 18V 3A 300KHz BUCK CONVERTER OUTPUT OCSET Feedback function test © JUNE 2008 ...
Page 9
... Under Voltage Lockout The under voltage lockout circuit of the AP1538 assures that the high-side MOSFET driver remains in the off state whenever the supply voltage drops below 3.3V. Normal operation resumes once V rises above 3 ...
Page 10
... Top Side Layout Guide Use vias to conduct the heat into the backside of PCB layer. The heat sink at output (SW) pins should be allowed for maximum solder-painted area. Bottom Side Layout Guide AP1538 Rev. 2 18V 3A 300KHz BUCK CONVERTER (Continued) Recommended exposed-pads gap: 30~40mil (0.75~1mm) Brown: IC exposed pads ...
Page 11
... Functional Description Option AP1538 Rev. 2 18V 3A 300KHz BUCK CONVERTER (Continued) Vcc Output AP1538 FB OCSET Figure: Layout numbering comparison www.diodes.com AP1538 Option + + JUNE 2008 © Diodes Incorporated V OUT C4 ...
Page 12
... Marking Information (1) SOP-8L Logo Part No. (2) SOP-8L-DEP Logo Part No. AP1538 Rev. 2 18V 3A 300KHz BUCK CONVERTER ( Top View ) 5 8 AP1538 YYWW SOP-8L ( Top View ) 5 8 AP1538 YYWW SOP-8L-DEP www.diodes.com AP1538 G : Green Internal code Xth week: 01~52 Year : " ...
Page 13
... SOP-8L 7°~9° 1.27typ 4.80/5.30 8x-0.41 6x-1.27 Land Pattern Recommendation (Unit: mm) (2) SOP-8L-DEP 8 1 0.3/0.5 1.27Typ. 4.85/4.95 2.05Typ. 1 0.20 8 1.7 1 Bottom view AP1538 Rev All Dimensions Gauge Plane Seating Plane 0.38/1.27 Detail "A" 7°~9° 0.35max. 45° 0.3/0.5 3.70/4.10 0. 1.8 1.8 1.65 0. EXPOSED PAD C L Top View ...
Page 14
... Diodes Incorporated and all the companies whose products are represented on our website, harmless against all damages. Diodes Incorporated products are not authorized for use as critical components in life support devices or systems without the expressed written approval of the President of Diodes Incorporated. AP1538 Rev. 2 18V 3A 300KHz BUCK CONVERTER IMPORTANT NOTICE ...