Product Specification
IXD3220/IXD3221
16V Input Voltage Step-Down DC/DC Controller
The IXD3220 series utilize PWM mode, while the
FEATURES
IXD3221 series utilize either PWM or PFM mode,
Operating Input Voltage Range: 2.8V ~ 16.0V
automatically switching from PWM to PFM at light
Output Voltage Range Externally Set: > 1.2V
loads to achieve high efficiency over a wide range of
load conditions.
Output Current: up to 3A
The IXD3220/221series A and C versions have soft
Reference Voltage: 0.9V 1.5%
start function internally set to 4 ms, and the
Oscillation Frequency: 300 kHz, 500 kHz and 1
IXD3220/221 series B and D versions allow set-up
MHz
soft start externally.
Operating Mode: PWM (IXD3220) or PWM/PFM
The built-in UVLO (Under Voltage Lock Out) function
automatically switching (IXD3221)
forces the external P-channel transistor in OFF state
Soft Start: 4 ms internal (IXD3220A/221A) or > 4
when input voltage becomes 2.3V or lower.
ms externally set (IXD3220B/221B)
If the FB pin is shorted to the Ground or the output
Protection: Integral and Short Circuit
voltage drops rapidly because of overload, resulting
Small Package: SOT-25, USP-6C
in V < 0.7 V, the external P-channel transistor is
FB
APPLICATION forced OFF and latched in this state.
The latching state does not mean a complete
Set top boxes
shutdown, but a state in which pulse output is
Digital TVs
suspended; but the internal circuitry remains in
DVD/HDD recorders
operation. To restart circuit, either VIN or CE pin
Various portable equipment
should be triggered.
DESCRIPTION
Integral Protection Circuit monitors the duty cycle at
EXT pin. In case of high load, when duty cycle ratio
The IXD3220/221 series are multi-purpose step-down
exceed maximum allowed value a certain amount of
DC/DC controllers, which require only a transistor, a
time (t ), the EXT pin latches at high level and
coil, a diode, and two capacitors connected externally PRO
keeps the external P-channel transistor in OFF state.
to create a high efficiency stable power supply with
To restart circuit, either VIN or CE pin should be
output current up to 3A. Low ESR ceramic capacitors
triggered.
can be used as an output capacitor.
For the applications with small dropout voltage,
The IXD3220/221 series has a 0.9 V (1.5 %)
working close to maximum allowed duty cycle ratio,
reference voltage, which allows set output voltage in
the IXD3220/221 series C or D versions without the
wide range using external resistive divider.
integral protection are recommended.
Switching frequency of 300 kHz, 500 kHz, and
1.0 MHz allows use of small external components.
TYPICAL APPLICATION CIRCUIT TYPICAL PERFORMANCE CHARACTERISTIC
Efficiency vs. Output Current
R requires with low ESR (ceramic) capacitors used as C Neither tantalum or
S L
aluminum capacitors require R
S
IXD3221A095MR - V = 3.3 V, f = 500 kHz, C = C = 47 F (OS-Con), L = 10
OUT OSC IN L
H (CDRH8D43, (SUMIDA), Q - CPH3308, C =1.0 F (ceramic), R =10
FB FB
PS034101-0515 PRELIMINARY 1 Product Specification
IXD3220/IXD3221
ABSOLUTE MAXIMUM RATINGS
PARAMETER SYMBOL RATINGS UNITS
V Pin Voltage V 0.3 ~ 18.0 V
IN IN
FB Pin Voltage V 0.3 ~ 18.0 V
RB
CE/C Pin Voltage CE 0.3 ~ 18.0 V
SS
EXT Pin Voltage V V 0.3 ~ V + 0.3 V
EXT SS OUT
EXT Pin Current I 100 mA
EXT
SOT-25 250
Power Dissipation P mW
D
USP-6C 100
0
Operating Temperature Range T 40 ~ + 85 C
OPR
0
Storage Temperature Range T 55 ~ +125 C
STG
ELECTRICAL OPERATING CHARACTERISTICS
0
IXD3220/221 A and C versions Unless otherwise specified, V = 5 V, Ta = 25 C
IN
PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT CIRCUIT
FB Voltage V 0.8865 0.9000 0.9135 V
FB
Input Voltage Range V 2.8 - 16.0 V
IN
UVLO Voltage
V 1.9 2.3 2.7 V
UVLO
(Minimum Operating Voltage)
Supply Current 2 I V = 5.0 V, V = 1.0 V ** A
DD2 IN FB
Standby Current I 0.1 1 A
STB
Oscillation Frequency f Connected to external components ** kHz
OSC
Maximum Duty Cycle Ratio D 100 - - %
MAX
PFM Duty Cycle Ratio D No load IXD3221 series only 15 25 35 %
PFM
EXT H ON Resistance R 6 10 16
EXTH
EXT L ON Resistance R 6 12 20
EXTL
Integral Protection Time (*2) t IXD3220/221 A series ** ms
PRO
Short-Circuit Protection V 0.7 V
SHRT
Soft-Start Time t ** ms
SS
Efficiency (*1) EFF1 92 %
FB Voltage Temperature
0
100 ppm/ C
Characteristics
CE High Voltage VCEH 1.2 V
CE Low Voltage V 0.3 V
CEL
CE High Current I V = V = 16 V -0.1 0.1 A
CEH IN CE
CE Low Current I V = 16 V, V = 0 V -0.1 0.1 A
CEL IN CE
FB High Current I V = V = 16 V -0.1 0.1 A
FBH IN CE
FB Low Current IFBL VIN = 16 V, VCE = 0 V -0.1 0.1 A
NOTE:
*1: EFF1 = {(output voltage) x (output current)} / {(input voltage) x (input current)} x 100
*2: No Integral protection function is available with the IXD3220/221 C series.
** Refer to the CHARACTERISTICS CHART BY OSCILLATION FREQUENCY
PS034101-0515 PRELIMINARY 2