Document
Preliminary
RT8101/A
12V Synchronous Buck PWM DC-DC
General Description
The RT8101/A are DC/DC synchronous buck PWM controllers with embedded driver support up to 12V+12V boot-strapped voltage for high efficiency power driving. The parts are with full functions of voltage regulation, power monitoring and protection into a single small footprint packages SOP-8 and SOP-8 (Exposed Pad). www.DataSheet4U.com The RT8101/A apply a high-gain voltage mode PWM control for simple application design. An internal 0.8V reference allows the output voltage to be precisely regulated to low voltage requirement. The parts are proposed with two type including RT8101 and RT8101A with fixed operating frequency of 300kHz and 600kHz respectively. Based on the features that RT8101/A offered, the parts provide an optimum solution between efficiency, total B.O.M. count, and cost.
Features
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Single 12V Bias Supply Drives All Low Cost N-MOSFETs High-Gain Voltage Model PWM Control 300kHz/600kHz Fixed Frequency Oscillator Fast Transient Response : `High-Speed GM Amplifier `Full 0 to 100% Duty Ratio `External Compensation in the Control Loop Internal Soft-Start Adaptive Non-Overlapping Gate Driver Over-Current Fault Monitor on MOSFET, No Current Sense Resistor Required RoHS Compliant and 100% Lead (Pb)-Free
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Applications
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Ordering Information
RT8101/A Package Type S : SOP-8 SP : SOP-8 (Exposed Pad) Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) 600kHz 300kHz
Note : RichTek Pb-free and Green products are : `RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. `Suitable for use in SnPb or Pb-free soldering processes. `100% matte tin (Sn) plating.
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Graphic Card Motherboard, Desktop Servers IA Equipments Telecomm Equipments High Power DC-DC Regulators
Pin Configurations
(TOP VIEW)
BOOT UGATE GND LGATE 2 3 4 8 7 6 5 PHASE COMP FB VCC
SOP-8
BOOT UGATE GND LGATE 2 3 4 GND
8 7 6 5
PHASE COMP FB VCC
SOP-8(Exposed Pad)
DS8101/A-01 March 2007
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RT8101/A
Typical Application Circuit
12V
Preliminary
RBOOT
VIN(+3.3V/+5V/+12V)
RT8101/A
1 5 6 BOOT VCC FB GND UGATE PHASE LGATE COMP 2 8 4 7 C PSC Q2 RUGATE Q1
CIN
LOUT VOUT
R
COUT
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Functional Pin Description
BOOT (Pin 1) Bootstrap supply for the upper gate driver. Connect the bootstrap capacitor between BOOT pin and the PHASE pin. The bootstrap capacitor provides the charge to turn on the upper MOSFET. UGATE (Pin 2) Upper gate driver output. Connect to gate of the highside power N-Channel MOSFET. This pin is monitored by the adaptive shoot-through protection circuitry to determine when the upper MOSFET is turned off. GND (Pin 3) Signal ground for the IC. LGATE (Pin 4) Lower gate driver output. Connect to the gate of the lowside power N-Channel MOSFET. This pin is monitored by the adaptive shoot-through protection circuitry to determine when the lower MOSFET is t.