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
types, which have a reference voltage of 0.8 V with ±
2.0% accuracy, the output voltage can be set from
0.9 V by using two external resistors.
Built-in transistors
Operating Input Voltage Range: 2.0 V ~ 6.0 V
(A/B/C types) or 1.8 V ~ 6.0 V (D/E/F/G types)
Output Voltage Range Externally Set: 0.8 V ~ 4.0
V (internally set) or 0.9 ~ 6.0 V (externally set)
The A/B/C/E/G types have a fixed output voltage
from 0.8 V to 4.0 V in increments of 0.05 V with
± 2.0% accuracy. The device requires only an
inductor and two externally connected ceramic
capacitors. The built-in oscillator, either 1.2 MHz or
3.0 MHz, can be selected.
Output Current: 600 mA
High Efficiency: 92%
Oscillation Frequency: 1.2 MHz, 3 MHz
Maximum Duty Cycle: 100%
The IXD3235 operates in PWM mode, the IXD3236
automatically switches between PWM/PFM modes,
and the IXD3237 allows switch manually between the
PWM and the automatic PWM/PFM switching control
modes. This allows fast response, low ripple, and
high efficiency over the full range of loads from light
to heavy.
Operating Modes: PWM, PWM/PFM auto select
or PWM/PFM manual select
Functions: Build-in Current Limit, Load Capacitor
Discharge, High Speed Soft start
Operating Ambient temperature: -40 ~ +850C
Packages: SOT-25, USP-6C, USP-6EL, WLP-5-03
EU RoHS Compliant, Pb Free
The soft start and current control functions are
internally optimized. All circuits are disabled in a
standby mode to reduce current consumption to less
than 1.0 μA.
APPLICATION
Mobile Phones
Bluetooth headsets
Digital home appliances
Office automation equipment
Various portable equipment
The B/F/G types have a 0.25 ms high-speed soft-
start for quick turn-on. The built-in Under Voltage
Lockout (UVLO) function forces the internal
P-channel transistor OFF, when input voltage
becomes 1.4 V or lower.
DESCRIPTION
The B to G types have the output capacitor CL
discharge circuitry, which allows fast CL discharge
when IC goes into standby mode.
The IXD3235/36/37 series is a group of synchronous-
rectification type DC/DC converters with a built-in
0.52 Ω N-channel synchronous rectification transistor
and 0.42 Ω P-channel switching transistor providing
up to 600 mA output current.
Device is available in four types of packages: SOT-
25, USP-6C, USP-6EL, and WLP-5-03.
TYPICAL APPLICATION CIRCUITS
TYPICAL PERFORMANCE CHARACTERISTIC
Efficiency vs. Output Current (fOSC = 1.2 MHz, VOUT = 1.8 V)
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
ZILOG [ ZILOG, INC. ]
