PAM2305D User Guide

PAM2305D
EVB User Guide
PAM2305D DFN EV Board User Guide
AE Department
1. Revision Information
Date
2011/07
Revision
V1.0
Description
Initial Release
Comment
2. PAM2305D General Description
The PAM2305D is a step-down current-mode, DC-DC converter. At heavy load, the constant frequency PWM
control performs excellent stability and transient response. To ensure the longest battery life in portable
applications, the PAM2305D provides a power-saving Pulse-Skipping Modulation (PSM) mode to reduce
quiescent current under light load operation to save power.
The PAM2305D supports a range of input voltages from 2.5V to 5.5V, allowing the use of a single Li+/Lipolymer cell, multiple Alkaline/NiMH cell, USB, and other standard power sources. The output voltage is
adjustable from 0.6V to the input voltage. All versions employ 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 0.1µA. Other key features include under-voltage lockout to prevent
deep battery discharge.
The PAM2305D is available in SOT23-5, DFN2x2 6-Pin and QFN3x3 16-Pin packages.
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
PAM2305D
EVB User Guide
3. Key Features
Efficiency up to 96%
Only 40uA(TYP.) Quiescent Current
Output Current: Up to 1A
Internal Synchronous Rectifier
1.5MHz Switching Frequency
Soft Start
z
z
z
z
z
z
Under-Voltage Lockout
Short Circuit Protection
Thermal Shutdown
5-pin Small SOT23-5, DFN2x2 6-Pin and
QFN3x3 16-Pin Packages
Pb-Free Package
z
z
z
z
z
4. EV Board Schematic
1
EN
Vin
2
1
3
EN 2
Vin
Vin 3
NC
FB
EN
GND
Vin
C1
SW
6 FB
5
4
L1
Vout
R1
C3
FB
C2
R2
5. EVB PAM2305D EB26AA Description
PAM2305D DFN EB26AA is an evaluation board for the PAM2305D DFN, a DC/DC converter. The board is
targeted to be used in providing a simple and convenient evaluation environment for the PAM2305D. Requires
parts, power supply connectors etc. on the board, which makes it easy to be evaluated.
.
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
PAM2305D
EVB User Guide
6. EV Board View
Top View
7. Resistor Select for Output Voltage Setting
VOUT = (1+R1/R2)×VREF
Vo
1.2V
1.5V
1.8V
2.5V
3.3V
R3
150k
150k
300k
475k
680k
(VREF = 0.6V)
R4
150k
100k
150k
150k
150k
L
1.0µH
2.2µH
2.2µH
4.7µH
4.7µH
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
PAM2305D
EVB User Guide
8. External Compnents Selection
Input & output Capacitors (C1, C2)
(1) For lower output ripple, low ESR is required.
(2) Low leakage current needed, X5R/X7R ceramic recommend, multiple capacitor parallel connection.
Feed forward capacitor (C3)
(1) Lower the output ripple.
(2) Low leakage current needed, 100pF, COH/CH ceramic recommend.
Output Voltage programmer resistors (R1, R2)
(1) For programmer output voltage.
(2) For accurate output voltage, 1% tolerance is required.
Inductor (L1)
(1) Low DCR for good efficiency.
(2) Inductance saturate current must higher than the output current.
9. Evaluation Board BOM List:
Item
Value
C1, C2
10µF
C3
100pF
L1
4.7µH
R1
680K
0603
1%
R2
150K
0603
1%
IC1
PCB
Type
X5R/X7R,
Ceramic/0603
COH/CH,
Ceramic/0402
Rating
6.3V
Description
Vender and Part No.
Input coupling CAP,
TAIYO YUDEN
Output CAP
JMK107 BJ106KA-T
6.3V
Feed forward CAP
1.2A
Inductor
TAIYO YUDEN
UMK105CH101JV-F
TAIYO YUDEN
NR3015T 4R7M
Voltage set RES
PAM2305D
PAM2305(D)DFN
EB26AA
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
PAM2305D
EVB User Guide
10. PCB Layout Example
Top Layer
Bottom Layer
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.