Diodes AP1604 User Manual

AP1604A
PWM/PFM DUAL MODE STEP-DOWN DC/DC
CONVERTER
Features
Input voltage range: 2.2V~5.5V (V
Oscillator frequency: 600KHz (Typ.)
Internal reference: 1.0V (Typ.)
High efficiency: 93% (Typ.)
Stand-by capability: I
Soft-start time set-up externally type possible
Current limit and thermal shutdown protection
Lead Free Package: SOT25
SOT25: Available in “Green” Molding Compound
(No Br, Sb)
Lead Free Finish/ RoHS Compliant (Note 1)
=2µA. (Typ.)
STB
OUT
Applications
Electronic Information Organizers
Palmtops
Cellular and portable phones
Portable Audio Systems
Various Multi-function Power Supplies
Ordering Information
AP1604A W X - 7
type)
General Description
The AP1604A series are multi-functional step-down DC/DC converters with built-in speed, low ON resistance drivers. It is capable to deliver more than 800mA output current with external coil, diode and ca pacitor.
Output voltage is set-up by the external resistors. (±2.5% accuracy). The 600K Hz AP1604A that can work out with sm all value external components comes out more compact board.
The device switches to and works under PFM mode with light loads. It keeps at high efficiency for both light loads and large output current.
AP1604A can be soft-start with a proper capacitor connected between CE/SS pin and ground. The stand-by current is less than 2uA when CE/SS pin is at “LOW” status. The device is forced to switch off as the voltage at that pin is lower than the stipulated voltage.
Package Lead Free
W : SOT25
L : Lead Free
Packing
7 : Tape & Reel
G : Green
Device
AP1604AWL-7
Lead-free
AP1604AWG-7
Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at http://www.diodes.com/products/lead_free.html
2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
http://www.diodes.com/datasheets/ap02001.pdf
Package
Code
W SOT25 W SOT25
Packaging
(Note 2)
.
.
Quantity Part Number Suffix
3000/Tape & Reel -7 3000/Tape & Reel -7
7” Tape and Reel
AP1604A Rev. 2 1 of 7 FEBRUARY 2009
Pin Assignment
(Top View)
FB
5 4
1 32
V
OUT
Pin Description
Pin Name Description
V
Output Voltage
OUT
GND Ground
VCC Input Supply
CE/SS Chip Enable / Soft Start
FB Feedback pin
Block Diagram
AP1604A
PWM/PFM DUAL MODE STEP-DOWN DC/DC
CONVERTER
CE/SS
AP1604A
V
GND
SOT25
CC
SV
CC
FB
Phase
Compensation
Current Limit
V
CC
+
ERR AMP
-
Soft
Start
CE/SS GND
Vref with
CE
AP1604A Rev. 2 2 of 7 FEBRUARY 2009
PWM/PFM
Controller
www.diodes.com © Diodes Incorporated
+
-
Comparator
Ramp Wave
Generator,
OSC
PWM
V
OUT
AP1604A
PWM/PFM DUAL MODE STEP-DOWN DC/DC
CONVERTER
Absolute Maximum Ratings (T
=25°C)
A
Symbol Parameter Ratings Units
VCC/SVCC VIN Pin Voltage -0.3 ~ 6.5 V
V
V
OUT
Pin Voltage -0.3 ~ VIN+0.3 V
OUT
VFB FB Pin Voltage -0.3 ~ VIN+0.3 V
V
CE/SS Pin Voltage -0.3 ~ VIN+0.3 V
CE/SS
PD Continuous Total Power Dissipation Internal limited TOP Operating Ambient Temperature -25 ~ +80 °C TST Storage Temperature Range -40 ~ +125 °C
Electrical Characteristics
V
= 5V, V
IN
Sym. Parameter Conditions Min Typ. Max Units
VFB FB 0.975 1.0 1.025 V
VIN Input Voltage 2.2 - 5.5 V
Line Regulation V Load Regulation I
V
UVLO
ICC Operating Current CE/SS = VIN,No Load - 100 150 μA
I
Supply Current
CCQ
I
Stand-by Current
STB
ICL Current Limit
Fosc Oscillator Frequency Load = 300mA, VIN= 5V, V MAXDTY Maximum Duty Ratio 85 90 - % PFMDTY PFM Duty Ratio No load 15 25 35 %
V
CE/SS ”High” Voltage
CEH
V
CE/SS ”Low” Voltage Same as V
CEL
EFFI Efficiency VCC= 5V, V
Rdson Rdson Condition I
2V, Load = 300mA, TA = 25°C
OUT
UVLO Voltage(min. operating voltage
= 2.2 ~ 5.5V, Load = 10mA - - 0.12 %
IN
= 10 ~ 800mA - - 1.2 %
OUT
V
, voltage required to maintain H at
CC
V
OUT
No external components, CE/SS = V
IN,VFB
= 1.2V No external components, CE/SS = 0V,V
FB
= 0V peak current V
IN
= 5V, V
OUT
= 2V
= 2V 500 600 700 kHz
OUT
Apply 1.4V (min.) to CE/SS, determine V
”High”
OUT
= 300mA, V
OUT
, determine V
CEH
= 3.3V, Load = 30 0mA - 93 - %
OUT
= 5V, V
IN
/”Low” - - 0.6 V
OUT
= 2V - 350 450 m
OUT
- - 2 V
- 90 120 μA
- 2 - μA
800 1000 1200 mA
1.4 - - V
AP1604A Rev. 2 3 of 7 FEBRUARY 2009
www.diodes.com © Diodes Incorporated
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