RICHTEK RT9228CS Datasheet
RT9228
Advanced PWM and Dual Linear Power Controller
General Description
The RT9228 is a 3-in-one power controller optimized
for high-performance microprocessor and computer
applications. The IC integrates a synchronous buck
PWM controller, a linear regulator, and a linear
controller as well as monitoring and protection
functions into a 24-pin SOP package. The PWM
controller regulates the microprocessor core voltage.
The linear regulator provides power for the clock
driver circuit and the linear controller regulates power
for the GTL bus.
The RT9228 features an Intel-compatible, TTL 5-bit
programmable DAC that adjusts the core voltage
from 2.1V to 3.5V in 0.1V increments and from 1.3V
to 2.05V in 0.05V steps. The 5-bit DAC has a typical
±1% tolerance. The linear regulator uses an internal
drive device to provide 2.5V ±2.5% output voltage.
The linear controller drives an external N-channel
MOSFET or a low cost NPN bipolar transistor to
provide 1.5V ±2.5%.
Features
z
3-in-one Regulated Voltages for Microprocessor
Core, Clock, and GTL
z
Compatible with HIP6018B
z
Power-good Output Voltage Monitor
Switching section
z
5-bit DAC Programmable from 1.3V to 3.5V
±±±±1% DAC Accuracy
z
z
Fast Transient Response
z
Full 0% to 100% Duty Cycle Driver
z
Fixed 200kHz Switching Frequency
z
Adaptive Non-overlapping Gate Driver
z
Over-current Monitor Uses MOSFET R
z
Over-voltage Protection Uses Lower MOSFET
Linear Section
z
User-adjustable Linear Regulator Output Voltage
z
MOSFET or NPN Driving Capability
z
Ultra Fast Response Speed
z
Under-voltage Protection
z
Internal Thermal Shutdown
DS(ON)
The RT9228 monitors all the output voltages. A
Power-good signal is issued when the core voltage is
within ±10% of the DAC setting and the other levels
are above their under-voltage levels. Additional build-
in over-voltage protection for the core output uses
the lower MOSFET to prevent output voltage above
115% of the DAC setting. The PWM over-current
function monitors the output current using the voltage
drop across the upper MOSFET’s R
DS(ON)
, which
eliminates the need for a current sensing resistor.
Ordering Information
RT9228
Package type
S : SOP-24
Operating temperature range
C: Commercial standard
Applications
Full Motherboard Power Regulation for Computer
z
Low-voltage Distribution Power Supplies
z
Pin Configurations
Part Number Pin Configurations
RT9228CS
(Plastic SOP-24)
VCC
VID4
VID3
VID2
VID1
VID0
PGOOD
FAULT
SS
NC
FB2 GND
VIN2
TOP VIEW
1
2
3
4
5
6
7
8
9
10
11
12 13
24
23
22
21
20
19
18
17
16
15
14
UGATE1
PHASE1
LGATE1
PGND
OCSET1
VSEN1
FB1
NC
FB3
GATE3
VOT2
DS9228-03 July 2001 www.richtek-ic.com.tw
1
RT9228
Absolute Maximum Ratings
z Supply Voltage +15V
z PGOOD, FAULT and GATE Voltage GND−0.3V to V
z Input, Output or I/O Voltage GND−0.3V to 7V
z Ambient Temperature Range 0°C to +70°C
z Junction Temperature Range 0°C to +125°C
z Storage Temperature Range −65°C to +150°C
z Lead Temperature (Soldering, 10 sec.) 300°C
z Package Thermal Resistance
SOP-24, θ
JA
Recommended Operating Conditions
z Supply Voltage +12V±10%
z Ambient Temperature Range 0°C to 70°C
z Junction Temperature Range 0°C to 125°C
CAUTION:
Stresses beyond the ratings specified in “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress only rating and operation of the device at these or any other conditions above those
indicated in the operational sections of this specification is not implied.
75°C/W
CC
+0.3V
Electrical Characteristics
(V
= 12V, PGND = 0V, TA = 25°C, unless otherwise specified)
CC
Parameter Symbol Test Conditions Min Typ Max Units
VCC Supply Current
Nominal Supply Current
I
CC
Power-On Reset
VCC Rising Threshold
VCC Falling Threshold
Rising VIN2 Under-voltage Threshold -- 2.8 -- V
VIN2 Under-voltage Hysteresis -- 0.5 --
Rising V
OCSET1
Threshold
Oscillator
Free Running Frequency 180 200 225
Ramp Amplitude
∆V
OSC
UGATE1, GATE3, LGATE1,
and VOUT2 Open
V
OCSET1
V
OCSET1
= 4.5V
= 4.5V
-- 10 -- mA
7.5 -- 9.5 V
7--9V
-- 1.25 --
-- 1.9 --
To be continued
V
V
kHz
V
P-P
www.richtek-ic.com.tw DS9228-03 July 2001
2
Parameter Symbol Test Conditions Min Typ Max Units
Reference and DAC
RT9228
DAC (VID0-VID4) Input Low Voltage -- -- 0.8
DAC (VID0-VID4) Input High Voltage 2.0 -- --
DACOUT Voltage Accuracy DACOUT = 2.05 ~ 3.50V -1 -- 1
DACOUT Voltage Accuracy DACOUT = 1.30 ~ 2.00V -1% -- 20mV
Reference Voltage (Pin FB2 and FB3)
V
REF
1.240 1.265 1.290
Linear Regulator
Regulation
10mA < I
VOUT2
< 150mA
-2.5 -- 2.5
Under-voltage Level FB2 Rising -- 75 87
Under-voltage Hysteresis -- 100 --
Over-current Protection
I
OVP
180 230 --
Over-current Protection During Start-up -- 700 --
Linear Controller
Regulation
VSEN3 = GATE3
GATE3
< 20mA
0 < I
-2.5 -- 2.5
Under-voltage Level FB3 Rising -- 75 87
Under-voltage Hysteresis -- 100 --
Output Drive Current
VIN2 – VOUT3 > 1.5V
20 40 --
V
V
%
-
V
%
%
mV
mA
mA
%
%
mV
mA
PWM Controller Error Amplifier
DC Gain -- 65 --
PWM Controller Gate Driver
UGATE Source
UGATE Sink
LGATE Source
LGATE Sink
R
UGATE1
R
UGATE1VUGATE1
VCC - V
VCC = 12V
I
VCC = 12V
LGATE1
R
LGATE1VLGATE1
V
LGATE1
UGATE1
= 1V
= 2V
= 1V
= 1V
-- 3 7
-- 3 7
-- 1 --
-- 2 6
Protection
V
Over-voltage Trip
OUT1
FAULT Souring Current
OCSET1 Current Source
Soft-start Current
I
OVP
I
OCSET
I
SS
VSEN1 Rising 112 115 120
V
V
FAULT
OCSET1
= 8V
VSS = 1V
= 4.5V
10 14 --
170 200 230
-- 11 --
Power Good
V
Upper Threshold
OUT1
V
Under Voltage
OUT1
V
Hysteresis (VSEN1/DACOUT)
OUT1
PGOOD Voltage Low
V
PGOOD
VSEN1 Rising 108 -- 112
VSEN1 Rising 89 -- 95
Upper/Lower Threshold -- 2 --
I
PGOOD
= -4mA
-- -- 0.5
dB
Ω
Ω
A
Ω
%
mA
µA
µA
%
%
%
V
DS9228-03 July 2001 www.richtek-ic.com.tw
3
Loading...