NQ04W33SKA10 Datasheet, PDF (9/13 Pages) SynQor Worldwide Headquarters – SMT Surface Mount

Technical Specification
Input: 2.4 - 6.0V
Outputs: 0.75 - 3.6V
Current: 10A
Package: SMT
BASIC OPERATION AND FEATURES
The NiQor series non-isolated converter uses a buck-converter
that keeps the output voltage constant over variations in line,
load, and temperature. The NiQor modules employ synchronous
rectification for very high efficiency.
Dissipation throughout the converter is so low that it does not
require a heatsink or metal baseplate for operation. The NiQor
converter can thus be built more simply and reliably using high
yield surface mount techniques on a single PCB substrate.
The NiQor series of SIPs and SMT converters uses the established
industry standard footprint and pin-out configurations.
CONTROL FEATURES
REMOTE ON/OFF: The ON/OFF input permits the user to con-
trol when the converter is on or off. There are currently two
options available for the ON/OFF input described in the table
below. Others may become available if demand exists.
Option Description
P Logic Positive/Open
O Logic Negative/Open
Pin-Open
Float
Voltage
5
0
Pin-Open
Converter
State
On
On
Pin Action
Pull Low = Off
Pull High = Off
OUTPUT VOLTAGE TRIM: The TRIM input permits the user to
adjust the output voltage according to the trim range specifica-
tions by using an external resistor. If the TRIM feature is not being
used, leave the TRIM pin disconnected.
TRIM-UP: To increase the output voltage from the nominal set-
point of 0.7525V using an external resistor, connect the resistor
R_trim-up between the TRIM and the Ground pin according to the
diagram below.
Vin
Vout
Sense+
On/Off
Trim
Gnd
R_trim-up
For a desired increase of the nominal output voltage, the value of
the resistor should be:
R_trim-up ⁼
21070 _{_ 5110}
V_DES - 0.7525
(W)
or
V_OUT ⁼ 0.7525 +
21070
(W)
R_trim-up + 5110
where _{VDES = Desired Output Voltage}
To maintain the accuracy of the output voltage over load current,
it is vital that any trim-up resistor be terminated directly to the con-
verter's ground foot, not at the connection to the load. A sepa-
rate Kelvin connection to the PCB pad for the ground foot is opti-
mal. Trim-down resistors should be terminated at the converter's
Sense+ pin.
We do not recommend bypassing the trim pin directly to ground
with a capacitor. The voltage gain from the trim pin to output is
rather large, 15:1. Ground bounce through a bypass capacitor
could introduce significant noise to the converter's control circuit.
PROTECTION FEATURES
Input Under-Voltage Lockout: The converter is designed to
turn off when the input voltage is too low, helping avoid an input
system instability problem, described in more detail in the appli-
cation note titled “Input System Instability”. The lockout circuitry
is a comparator with DC hysteresis. When the input voltage is
rising, it must exceed the typical Turn-On Voltage Threshold value
(listed on the specification page) before the converter will turn
on. Once the converter is on, the input voltage must fall below
the typical Turn-Off Voltage Threshold value before the converter
will turn off.
Output Current Limiting: To provide protection in an output
over load fault condition, the unit is equipped with internal over-
current protection. When the over-current protection is triggered,
the unit enters hiccup mode. The units operate normally once the
fault condition is removed.
Internal Over-Voltage Protection: To fully protect from
excessive output voltage, the NQ04 series contains an Output
Over-Voltage Shutdown circuitry.
This OVP is independent of the trimmed setpoint. As such, the
converter's load is protected from faults in the external trim cir-
cuitry (such as a trim pin shorted to ground). Since the setpoint
of this OVP does not track trim, it is set at 4.2V, in the wide-trim
W33 model.
Product # NQ04W33SKA10
Phone [phone]
www.synqor.com
Doc.# 005-2NK4S3E Rev. A 11/26/07
Page 9