ZXSC420E6TA Diodes Zetex, ZXSC420E6TA Datasheet - Page 5

• Manufacturer Part Number: ZXSC420E6TA
• Description: IC CONVERTER BOOST SOT23-6
• Manufacturer: Diodes Zetex
• Type: Step-Up (Boost)r

Specifications of ZXSC420E6TA

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: Adjustable
• Current - Output: 300mA
• Frequency - Switching: Up to 200kHz
• Voltage - Input: 1.8 ~ 8 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Power - Output: 450mW
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ZXSC420E6TATR

PIN DESCRIPTIONS
APPLICATIONS INFORMATION
Switching transistor selection
The choice of switching transistor has a major impact
on the converter efficiency. For optimum performance,
a bipolar transistor with low V
required. The V
important parameter as this sees the full output
voltage when the transistor is switched off. Zetex
SuperSOT™ transistors are an ideal choice for this
application.
Schottky diode selection
As with the switching transistor, the Schottky rectifier
diode has a major impact on the converter efficiency. A
Schottky diode with a low forward voltage and fast
recovery time should be used for this application.
The diode should be selected so that the maximum
forward current rating is greater or equal to the
maximum peak current in the inductor, and the
maximum reverse voltage is greater or equal to the
output voltage. The Zetex ZHCS Series meet these
needs.
Combination devices
To minimise the external component count Zetex
recommends the ZX3CDBS1M832 combination of
NPN transistor and Schottky diode in a 3mm x 2mm
MLP package. This device is recommended for use in
space critical applications.
The IC is also capable of driving MOSFETs. Zetex
recommends the ZXMNS3BM832 combination of low
threshold voltage N-Channel MOSFET and Schottky
diode in a 3mm x 2mm MLP package. This device is
recommended for use in space critical applications.
ISSUE 2 - May 2003
Pin No.
1
2
3
4
5
6
CEO
Name
V
GND
STDN/EOR
SENSE
V
DRIVE
of the switching transistor is also an
CC
FB
CE(SAT)
and high gain is
Description
Supply voltage, 1.8V to 8V.
Ground
Shutdown ZXSC410 / End of regulation ZXSC420
Inductor current sense input. Internal threshold voltage set to
28mV. Connect external sense resistor.
Reference voltage. Internal threshold set to 300mV. Connect
external resistor network to set output voltage.
Drive output for external switching transistor. Connect to base or
gate of external switching transistor.
5
R SENSE
Inductor Selection
The inductor value must be chosen to satisfy
performance, cost and size requirements of the overall
solution.
Inductor selection has a significant impact on the
converter performance. For applications where
efficiency is critical, an inductor with a series resistance
of 500m
A list of recommended inductors is listed in the table
below:
Peak current definition
In general, the I
the switching transistor, Q1, is in full saturation with
maximum output power conditions, assuming
worse-case input voltage and transistor gain under all
operating temperature extremes.
Once I
determined by:
CMD4D11-100MC Sumida
CMD4D11-220MC Sumida
LPO2506OB-103
ST2006103
Part No.
PK
or less should be used.
V SENSE
is decided the value of R
I PK
PK
value must be chosen to ensure that
Coilcraft
Standex
Electronics Inc
Manufacture
S E M I C O N D U C T O R S
ZXSC410
ZXSC420
10µH 0.5 0.457
22µH 0.4 0.676
10µH 1.0 0.24
10µH 0.6
SENSE
L
I
(A)
PK
can be
R
( )
0.1
DC