FAN5234QSC_Q Fairchild Semiconductor, FAN5234QSC_Q Datasheet

Switching Converters, Regulators & Controllers PWM Controller

FAN5234QSC_Q

Manufacturer Part Number
FAN5234QSC_Q
Description
Switching Converters, Regulators & Controllers PWM Controller
Manufacturer
Fairchild Semiconductor
Datasheet

Specifications of FAN5234QSC_Q

Lead Free Status / Rohs Status
Lead free / RoHS Compliant
© 2004 Fairchild Semiconductor Corporation
FAN5234 • Rev. 2.0.0
FAN5234
Dual Mobile-Friendly PWM / PFM Controller
Features
Applications
Related Resources
Ordering Information
FAN5234MTCX
Part Number
Wide Input Voltage Range for Mobile Systems:
2V to 24V
Excellent Dynamic Response with Voltage Feed-
Forward and Average-Current-Mode Control
Lossless Current Sensing on Low-Side MOSFET or
Precision Over-Current via Sense Resistor
V
Power-Good Signal
Light-Load Hysteretic Mode Maximizes Efficiency
300KHz or 600KHz Operation
TSSOP16 Package
Mobile PC Regulator
Handheld PC Power
Application Note — AN-6002 Component
Calculations and Simulation Tools for FAN5234
or FAN5236
Application Note — AN-1029 Maximum Power
Enhancement Techniques for SO-8 Power
MOSFET
CC
Under-Voltage Lockout
Temperature
-10 to +85°C
Operating
Range
16-Lead, Thin-Shrink Small-Outline Package (TSSOP)
Description
The FAN5234 PWM controller provides high efficiency
and regulation with an adjustable output from 0.9V to
5.5V required to power I/O, chip-sets, memory banks, or
peripherals in high-performance notebook computers,
PDAs,
rectification and hysteretic operation at light loads
contribute to a high efficiency over a wide range of
loads. The Hysteretic Mode of operation can be
disabled if PWM Mode is desired for all load levels.
Efficiency is further enhanced by using the MOSFET’s
R
Feed-forward ramp modulation, average current mode
control, and internal feedback compensation provide
fast response to load transients. The FAN5234 monitors
these outputs and generates a PGOOD (power-good)
signal when the soft-start is completed and the output is
within ±10% of its set point. A built-in over-voltage
protection prevents the output voltage from going above
120% of the set point. Normal operation is automatically
restored when the over-voltage conditions cease.
Under-voltage protection latches the chip off when the
output drops below 75% of its set value after the soft-
start sequence is completed. An adjustable over-current
function monitors the output current by sensing the
voltage drop across the lower MOSFET.
DS(ON)
Package
as a current-sense component.
and
internet
appliances.
Packing Method
Tape and Reel
November 2010
Synchronous
www.fairchildsemi.com

Related parts for FAN5234QSC_Q

FAN5234QSC_Q Summary of contents

Page 1

... Operating Part Number Temperature Range FAN5234MTCX -10 to +85°C © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 Description The FAN5234 PWM controller provides high efficiency and regulation with an adjustable output from 0.9V to 5.5V required to power I/O, chip-sets, memory banks, or peripherals in high-performance notebook computers, ...

Page 2

... Typical Application VIN (BAT TERY 24V VCC + ILIM SS1 FPWM 16 R4 AGND 8 PGOOD 2 Block Diagram © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 VIN Q1A FA N5 234 HDRV Q1B LDRV 10 PGND 9 ISNS 12 VSEN 6 VOUT 5 Figure 1. 1.18V Output Regulator Figure 2. Block Diagram ...

Page 3

... MOSFET. 15 BOOT BOOT. Positive supply for the upper MOSFET driver. Connect as shown in Figure 2. Forced PWM Mode. When logic HIGH, inhibits the regulation from entering Hysteretic 16 FPWM Mode. © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 VIN FPWM 1 16 PGOOD BOOT ...

Page 4

... Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings. Symbol V V Supply Voltage Supply Voltage Ambient Temperature A Θ Thermal Resistance, Junction to Ambient JA © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 Parameter Parameter Min. 4.75 4 Min. Max. 6 6.5 -0.3 V +0.3 CC -10 +150 ...

Page 5

... Under-Voltage Shutdown TSD I Over-Current Threshold SNS UVLO Over-Voltage Threshold Output Drivers HDRV Output Resistance LDRV Output Resistance © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 Conditions Min. LDRV, HDRV Open; V Forced Above SEN Regulation Point Shutdown (EN-0) VIN Pin = Input Voltage ...

Page 6

... Upper Threshold PGOOD Output Low Leakage Current Soft-Start Voltage, PGOOD Enabled EN, FPWM Inputs V Input High INH V Input Low INL © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 (Continued) Conditions % of Set Point, 2µs Noise Filter % of Set Point, 2µs Noise Filter I = 4mA PGOOD V ...

Page 7

... µF. 0.9 SS © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 When SS reaches 1.5V, the power-good outputs are enabled and Hysteretic Mode is allowed. The converter is forced into PWM Mode during soft-start. Operation Mode Control The mode-control circuit changes the converter’s mode ...

Page 8

... MAX ) ⎜ ⎟ = − R 100 ⎜ ⎟ SENSE μ 150 A ⎝ ⎠ © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 PWMMode HystereticMode Setting the Current Limit A ratio of I established when a 0.9V internal reference drives the ILIM pin LIM I Since the tolerance on the current limit is largely ...

Page 9

... The adaptive gate control logic translates the internal PWM control signal into the MOSFET gate drive signals, providing necessary amplification, level shifting, and shoot-through protection. It also has functions that help optimize the IC performance over a wide range of © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0 ISNS 4 ...

Page 10

... drops below the under-voltage threshold, the OUT chip shuts down immediately. © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 Over-Current Sensing If the circuit's current-limit signal (“I is HIGH at the beginning of a clock cycle, a pulse- skipping circuit is activated and HDRV is inhibited. The circuit continues to pulse skip in this manner for the next eight clock cycles ...

Page 11

... SW Therefore; L ≈ 8 µH © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 Output Capacitor Selection The output capacitor serves two major functions in a switching power supply. Along with the inductor, it filters the sequence of pulses produced by the switcher and it supplies the load transient currents ...

Page 12

... Figure 9. Switching Losses and ISS HDRV SW Figure 10. Drive Equivalent Circuit © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 The driver’s impedance and C period is controlled by the driver's impedance and Q vs. time Since most current assumption for the driver to simplify the ). calculation ...

Page 13

... It is not recommended to use high density interconnect systems, or micro-vias, on these signals. The use of blind or buried vias should be limited to the low-current signals only. The use of normal thermal vias is at the discretion of the designer. © 2004 Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 Qty. Ref. Vendor ...

Page 14

... Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’ ...

Page 15

... Fairchild Semiconductor Corporation FAN5234 • Rev. 2.0.0 15 www.fairchildsemi.com ...

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