Product Specification
IXD3235/36/37
Synchronous 600 mA Step-Down DC/DC Converter
Operating voltage range is from 2.0 V to 6.0 V (A
FEATURES
C types) or 1.8 V to 6.0 V (D G types). For the D/F
Built-in transistors
types, which have a reference voltage of 0.8 V with
Operating Input Voltage Range: 2.0 V ~ 6.0 V
2.0% accuracy, the output voltage can be set from
(A/B/C types) or 1.8 V ~ 6.0 V (D/E/F/G types)
0.9 V by using two external resistors.
Output Voltage Range Externally Set: 0.8 V ~ 4.0
The A/B/C/E/G types have a fixed output voltage
V (internally set) or 0.9 ~ 6.0 V (externally set)
from 0.8 V to 4.0 V in increments of 0.05 V with
Output Current: 600 mA
2.0% accuracy. The device requires only an
High Efficiency: 92%
inductor and two externally connected ceramic
capacitors. The built-in oscillator, either 1.2 MHz or
Oscillation Frequency: 1.2 MHz, 3 MHz
3.0 MHz, can be selected.
Maximum Duty Cycle: 100%
The IXD3235 operates in PWM mode, the IXD3236
Operating Modes: PWM, PWM/PFM auto select
automatically switches between PWM/PFM modes,
or PWM/PFM manual select
and the IXD3237 allows switch manually between the
Functions: Build-in Current Limit, Load Capacitor
PWM and the automatic PWM/PFM switching control
Discharge, High Speed Soft start
modes. This allows fast response, low ripple, and
0
Operating Ambient temperature: -40 ~ +85 C
high efficiency over the full range of loads from light
Packages: SOT-25, USP-6C, USP-6EL, WLP-5-03
to heavy.
EU RoHS Compliant, Pb Free
The soft start and current control functions are
internally optimized. All circuits are disabled in a
APPLICATION
standby mode to reduce current consumption to less
Mobile Phones
than 1.0 A.
Bluetooth headsets
The B/F/G types have a 0.25 ms high-speed soft-
Digital home appliances
start for quick turn-on. The built-in Under Voltage
Office automation equipment
Lockout (UVLO) function forces the internal
Various portable equipment
P-channel transistor OFF, when input voltage
DESCRIPTION
becomes 1.4 V or lower.
The B to G types have the output capacitor C
The IXD3235/36/37 series is a group of synchronous- L
discharge circuitry, which allows fast C discharge
rectification type DC/DC converters with a built-in L
when IC goes into standby mode.
0.52 N-channel synchronous rectification transistor
and 0.42 P-channel switching transistor providing
Device is available in four types of packages: SOT-
up to 600 mA output current.
25, USP-6C, USP-6EL, and WLP-5-03.
TYPICAL APPLICATION CIRCUITS TYPICAL PERFORMANCE CHARACTERISTIC
Efficiency vs. Output Current (f = 1.2 MHz, V = 1.8 V)
OSC OUT
PWM/PFM Automatic Switching mode
IXD3235/36/37 A, B, C, E, and G types
IXD3235/36/37 D and F types
PS034201-0515 PRELIMINARY 1
Product Specification
IXD3235/36/37
ABSOLUTE MAXIMUM RATINGS
PARAMETER SYMBOL RATINGS UNITS
V Pin Voltage V 0.3 ~ 6.5 V
IN IN
1
L Pin Voltage V 0.3 ~ V + 0.3 V
X LX IN
V Pin Voltage V 0.3 ~ 6.5 V
OUT OUT
FB Pin Voltage V 0.3 ~ 6.5 V
FB
CE/MODE Pin Voltage V 0.3 ~ 6.5 V
CE
Lx Pin Current I 1500 mA
LX
SOT-25 250
USP-6C 120
Power Dissipation P mW
D
USP-6EL 120
WLP-5-03 750
0
Operating Temperature Range T 40 ~ + 85 C
OPR
0
Storage Temperature Range T 50 ~ +125 C
STG
ELECTRICAL OPERATING CHARACTERISTICS
0
IXD3235/36/37 A series, V = 1.8 V, Ta = 25 C
OUT
PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT CIRCUIT
Operating Voltage Range V 2.0 - 6.0 V
IN
Output Voltage V V = V = 5.0 V, I = 30 mA 1.764 1.800 1.836 V
OUT IN CE OUT
9)
Maximum Output Current I V = V + 2.0 V, V = 1.0 V 600 mA
OUT_MAX IN OUT(E) CE
1), 11)
UVLO Voltage V V = V , V = 0 1.00 1.40 1.78 V
UVLO CE IN OUT
IXD323xA18Cxx 15 33
Supply
I V = V = 5.0 V, V = V x 1.1 V A
Q IN CE OUT OUT(E)
Current
IXD323xA18Dxx 21 35
Standby Current I V = 5.0 V, V = 0 V, V = V x 1.1 V 0 1.0 A
STB IN CE OUT OUT(E)
IXD323xA18Cxx 1020 1220 1380
Oscillation
f V = V + 2 V, V = 1.0 V, I = 100 mA kHz
OSC IN OUT(E) CE OUT
Frequency
IXD323xA18Dxx 2550 3000 3460
PFM
IXD323xA18Cxx 120 160 200
12)
Switching I V = V = V + 2 V, , I = 1 mA (see table A) mA
PFM IN CE OUT(E) OUT
IXD323xA18Dxx 170 220 270
Current
12)
P-channel ON time maximum t V = V = (see table B), I = 1 mA 2D 3D
PON_MAX IN CE OUT max MAX
Maximum Duty Cycle Ratio D V = V = 5.0 V, V = V x 0.9 V 100 %
MAX IN CE OUT OUT(E)
Minimum Duty Cycle Ratio D V = V = 5.0 V, V = V x 1.1 V 0 %
MIN IN CE OUT OUT(E)
IXD323xA18Cxx 92
2)
Efficiency EFFI V = V = V + 1.2 V, I = 100 mA %
IN CE OUT(E) OUT
IXD323xA18Dxx 86
3)
L H ON Resistance 1 R V = V = 5.0 V, V = 0 V, I = 100 mA 0.35 0.55
X LXH1 IN CE OUT LX
3)
L H ON Resistance 2 R V = V = 3.6 V, V = 0 V, I = 100 mA 0.42 0.67
X LXH2 IN CE OUT LX
4)
L L ON Resistance 1 R V = V = 5.0 V 0.45 0.65
X LXL1 IN CE
4)
L L ON Resistance 2 R V = V = 3.6 V 0.52 0.77
X LXL2 IN CE
5)
L H Leakage Current I V = V = 5.0 V, V = 0 V, V = 5.0 V 0.01 1.0 A
X LXH IN CE OUT LX
5)
L L Leakage Current I V = V = 5.0 V, V = 0 V, V = 5.0 V 0.01 1.0 A
X LXH IN CE OUT LX
10) 8)
Current Limit I V = V = 5.0 V, V = V x 0.9 V 900 1050 1350 mA
LIM IN CE OUT OUT(E)
Output Voltage Temperature
0 0 0
-40 C T 85 C, I = 30 mA 100 ppm/ C
OPR OUT
Characteristics
14)
CE H Voltage V V = 0 V 0.65 6.0 V
CEH OUT
15)
CE L Voltage V V = 0 V 0 0.25 V
CEL OUT
6), 13)
PWM mode Start Voltage V I = 1 mA V -1.0
PWM OUT IN
PWM/PFM mode V
IN
V I = 1 mA
6), 13) PFM OUT
Start Voltage 0.25
CE H Current I V = V = 5.0 V, V = 0 V -0.1 0.1 A
ENH IN CE OUT
PS034201-0515 PRELIMINARY 2