PAM2421 User Guide

PAM2421
EVB User Guide
PAM2421 EV Board User Guide
AE Department
1. Revision Information
Date
2011/09
Revision
V1.0
Description
Initial Release
Comment
2. PAM2804 General Description
The PAM2421 devices are high-performance, fixed frequency, current-mode PWM step-up DC/DC
converter that incorporate internal power MOSFET. The PAM2421 includes an integrated power
MOSFET that supports peak currents of up to 3A.
The PAM2421 utilizes simple external loop compensation allowing optimization between component
size, cost, and AC performance across a wide range of applications. Additional functions include an
externally programmable soft-start function for easy inrush current control, internal over-voltage
protection (OVP), cycle-by-cycle current limit protection, under voltage lock-out and thermal shutdown.
The PAM2421 is available in the small SOP-8(EP) package.
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.
PAM2421
EVB User Guide
3. Key Features
 Greater than 90% Efficiency
 Programmable Soft Start Function
 Adjustable Output Voltage Up to 24V
 Thermal Shutdown
 Internal 24V Power MOSFET
 Under Voltage Lockout
 520kHz Frequency
 Over Current Protection
 Built-in Over Voltage Protection (OVP)
 SOP-8 (EP) Package
 Open Protection
4. EV Board Schematic
Vin
C2
C1
C3
C4
EN
1
Vcc
2
EN
3
D1
L1
R1
C9
C10
D2
C11
SW
VIN
SS
EN
FB
C7
Vcc
EN
R4
R2
C5
R3 C8
IC1
PGND
Vo
Comp
R5
AGND
C6
5. EVB PAM2421 TB15AA Description
PAM2421 TB15AA is an evaluation board for the PAM2421, a DC/DC boost converter. The board is
targeted to be used in providing a simple and convenient evaluation environment for the PAM2421.
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.
PAM2421
EVB User Guide
6. EV Board View
EV Board Operational Sequence:
a. Connect EN to high (H side).
b. Connect load to output terminal.
c.
Connect Vin and GND to power supply. Vin=5V or Li-ion battery.
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.
PAM2421
EVB User Guide
7. External Components Selection
Input & output Capacitors (C1, C2, C3, C9, C10, C11)
(1) For lower output ripple, low ESR is required (C2, C3, C9, C10), Low leakage current needed,
X5R/X7R ceramic recommend.
(2) Provide large power, large capacitance electrolytic capacitor recommend parallel connection to the
ceramic capacitor (C1, C11).
Vin filter (R1, C4)
(1) RC filter to filtering the switching noise on IC supply, 10Ω and 1uF ceramic capacitor recommend.
Compensation net (R2, C5, C6)
(1) R2 56kΩ, C5 2.2nF, C6 47pF recommended.
Soft start (C7)
(1) C7 0.1uF recommended.
Schottky Diode (D1, D2)
(1) SS34 3A/40V schottky diode recommended.
(2) B340 3A/40V schottky diode recommended.
Feed forward capacitor (C8)
(1) Lower the output ripple, low leakage current needed, using according to application.
Output Voltage programmer resistors (R3, R4, R5)
(1) For programmer output voltage
(2) For accurate output voltage, 1% tolerance is required. Vo=1.262*(1+R3/R4//R5).
Inductor (L1)
(1) Low DCR for good efficiency
(2) Inductance saturate current must higher than the output current
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.
PAM2421
EVB User Guide
8. Evaluation Board BOM List
Item
C1, C11
Value
470µF
Type
Ecap D10*20mm
X5R/X7R,
Ceramic/0805
X5R/X7R,
Ceramic/1206
X5R/X7R,
Ceramic/0603
X5R/X7R,
Ceramic/0603
Rating
25V
Description
C2, C3
10µF
16V
Input coupling CAP
C9, C10
10µF
25V
Output coupling
CAP,
C4
1.0µF
25V
Vin coupling CAP
C5
2.2nF
C6
47pF
C0H, Ceramic/0603
50V
C7
0.1µF
X5R/X7R,
Ceramic/0805
50V
L1
6.8µH
D2
D1
R1
R2
R3
R4
R5
C8
IC1
PCB
3A/40V
NC
10
56K
100K
10K
NC
620K
SS34
0805
0805
0805
0805
0805
0805
PAM2421
PAM2421 TB15AA
50V
>3A
Inductor
SMC
SMC
5%
1%
1%
1%
1%
1%
PSOP-8
Schottky diode
Vender and Part No.
TAIYO YUDEN
EMK212ABJ106KD-T
TAIYO YUDEN
TMK316BJ106KL-T
TAIYO YUDEN
TMK107B7105KA-T
TAIYO YUDEN
UMK107SD222KA-T
TAIYO YUDEN
UMK105CH470JV-F
TAIYO YUDEN
UMK212B7104KG-T
WURTH
7447709006
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.
PAM2421
EVB User Guide
9. 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.