background image

AP3445/L 

EVB  User  Guide 

 

This EVB user guide contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.   
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product. 

 

1 of 5 

www.diodes.com

   

October 2018 

© Diodes Incorporated

 

 

AP3445/L EVB User Guide 

AE Department 

1.

 

AP3445/L Revision Information 

Date 

Revision 

Description 

Comment 

2017/10 

V1.0 

Initial Release 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.

 

AP3445/L General Description 

The AP3445/L is a 2A step-down DC-DC converter. At heavy load, the constant frequency PWM control 

performs excellent stability and transient response. No external compensation components are required. 

The AP3445/L supports a range of input voltages from 2.7V to 5.5V, allowing the use of a single Li+/Li- 

polymer  cell,  multiple  Alkaline/NiMH  cell,  and  other  standard  power  sources.  The  output  voltage  is 

adjustable from 0.6V to the input voltage. The AP3445/L employs internal power switch and synchronous 

rectifier  to  minimize  external  part  count  and  realize  high  efficiency.  During  shutdown,  the  input  is 

disconnected  from  the  output  and  the  shutdown  current  is  less  than  1μA.  Other  key  features  include 

over-temperature and short circuit protection, and under-voltage lockout to prevent deep battery discharge.   

The  AP3445/L  delivers  2A  maximum  output  current  while  consuming  only  55μA  of  no-load  quiescent 

current. Ultra-low RDS(ON) integrated MOSFETs and 100% duty cycle operation make the AP3445/L an 

ideal  choice  for  high  output  voltage,  high  current  applications  which  require  a  low  dropout  threshold. 

Pulse skip mode allows to maintain high efficiency at light-load conditions.   

The AP3445/L is available in TSOT23-6 package. 

Summary of Contents for AP3445/L

Page 1: ...V to 5 5V allowing the use of a single Li Li polymer cell multiple Alkaline NiMH cell and other standard power sources The output voltage is adjustable from 0 6V to the input voltage The AP3445 L employs internal power switch and synchronous rectifier to minimize external part count and realize high efficiency During shutdown the input is disconnected from the output and the shutdown current is le...

Page 2: ...equency Internal Soft Start No External Compensation Required Current Limit Protection Short Circuit Protection AP3445L Latch Off Protection AP3445 Hiccup Mode Protection Over Voltage Protection AP3445L Latch Off Protection AP3445 Non Latch Off Protection Thermal Shutdown 4 AP3445 L EV Board Schematic R1 R2 VIN EN LX FB L1 2 2uH CIN 22uF VIN 2 7V to 5 5V GND COUT 22uFx2 VOUT 1 8V ON AP3445 L C1 22...

Page 3: ... diodes com October 2018 Diodes Incorporated 6 AP3445 L EV Board View 7 Setting the Output Voltage of AP3445 L The output voltage is calculated as below 2 2 1 6 0 R R R VOUT First select a value for R2 Then R1 is determined The output voltage is given by Table 1 Vo R1 R2 C3 1 0V 67KΩ 100 KΩ 22pF 1 2V 100KΩ 100 KΩ 22 pF 1 5V 150KΩ 100 KΩ 22 Pf 1 8V 200 KΩ 100 KΩ 22 pF 2 5V 317KΩ 100KΩ 22 pF 2 8V 36...

Page 4: ...kage current needed X5R X7R ceramic recommend multiple capacitor parallel connection 3 The Cin and Cout capacitances are greater than 22uF and 44uF respective 2 Output voltage programmer resistors R1 R2 1 For programmer output voltage 2 For accurate output voltage 1 tolerance is required 3 Inductor L 1 Low DCR for good efficiency 2 Inductance saturate current must higher than the output current 3 ...

Page 5: ...corporated 9 EV Board BOM List for AP3445 L Item Value Type Rating Description Description C1 22uF X5R X7R Ceramic 1206 10V Input coupling CAP C3 C4 22uF X5R X7R Ceramic 1206 6 8V Output coupling CAP L 2 2uH 4030 5 2A Inductor Wü rth PART 74438357022 R1 200K 0805 1 Voltage set RES R2 100K 0805 1 R3 100K 0805 1 Power Good RES C2 22pF 0805 Feedback CAP U1 AP3445 TSOT23 6 Diodes BCD Note The present ...

Reviews: