UNISEM US3021M

US3021M
5 BIT PROGRAMMABLE SYNCHRONOUS BUCK
PLUS TRIPPLE LDO CONTROLLER
PRELIMINARY DATASHEET
FEATURES
DESCRIPTION
Provides Single Chip Solution for Vcore,
GTL+ ,AGP Bus, and 1.8V
Automatic Voltage Selection for AGP slot
Vddq supply
Linear regulator controller on board for 1.8V
Designed to meet Intel Latest VRM specification for next generation micrprocessors
On board DAC programs the output voltage
from 1.3V to 3.5V
Linear regulator controller on board for 1.5V
GTL+ supply
Loss less Short Circuit Protection for all
outputs
Synchronous operation allows maximum
efficiency
Patented architecture allows fixed frequency
operation as well as 100% duty cycle during
dynamic load
Minimum part count
Soft Start
High current totem pole driver for direct
driving of the external Power MOSFET
Power Good function Monitors all Outputs
OVP Circuitry Protects the Switcher Output
and generates a Fault output
APPLICATIONS
Total Power Soloution for Next Generation Intel
Processor application
The US3021M controller IC is specifically designed to
meet Intel specification for next generation microprocessor applications requiring multiple on board regulators . The US3021M provides a single chip controller IC for the Vcore , 3LDO controllers, one with the
automatic select pin that connects to the TYPE DETECT pin of the AGP slot for the AGP Vddq supply,
one for GTL+ and the other for the 1.8V chip set
regulator as required for the next generation PC
applications. The US3021M uses N ch MOSFET as
pass transistor for Vout2(Vddq), Vout3(1.5V) and
Vout4(1.8V). No external resistor divider is necessary for any of the regulators. The switching regulator
feature a patented topology that in combination with a
few external components as shown in the typical application circuit ,will provide well in excess of 20A of output current for an on- board DC/DC converter while automatically providing the right output voltage via the 5 bit
internal DAC .The US3021M also features, loss less current sensing for both switcher by using the Rds-on
of the high side Power MOSFET as the sensing resistor, an output under voltage shutdown that detects short circuit condition for the linear outputs
and latches the system off, and a Power Good window comparator that switches its open collector output
low when any one of the outputs is outside of a pre programmed window.
TYPICAL APPLICATION
5V
3.3V
LINEAR
CONTROL
Vout2
SWITCHER
CONTROL
Vout1
US3021M
LINEAR
CONTROL
LINEAR
CONTROL
Vout3
Vout4
3021Mapp3-1.1
PACKAGE ORDER INFORMATION
Ta (°C)
0 TO 70
Rev. 1.3
12/8/00
Device
US3021MCW
Package
28 pin Plastic SOIC WB
4-1
US3021M
ABSOLUTE MAXIMUM RATINGS
V5 supply Voltage ........................................... 7V
V12 Supply Voltage ............................................ 20V
Storage Temperature Range ................................. -65 TO 150°C
Operating Junction Temperature Range .......... 0 TO 125°C
PACKAGE INFORMATION
28 PIN WIDE BODY PLASTIC SOIC (W)
TOP VIEW
Drive2 1
28 V12
Fix 2
27 UGate
VID4 3
26 Phase
VID3 4
25 LGate
VID2 5
24 PGnd
VID1 6
23 OCSet
VID0 7
22 Vsen1
PGood 8
21 Fb
SD 9
20 V5
Vsen2 10
19 Vsen3
Select 11
18 Drive3
SS 12
Fault / Rt 13
Vsen4 14
17 Gnd
16 NC
15 Drive4
θJA =80°C/W
ELECTRICAL SPECIFICATIONS
Unless otherwise specified ,these specifications apply over ,V12 = 12V, V5 = 5V and Ta=0 to 70°C. Typical values
refer to Ta =25°C. Low duty cycle pulse testing are used which keeps junction and case temperatures equal to the
ambient temperature.
PARAMETER
SYM TEST CONDITION
MIN
TYP
MAX
UNITS
Supply UVLO Section
UVLO Threshold-12V
Supply ramping up
10
V
UVLO Hysterises-12V
0.6
V
UVLO Threshold-5V
Supply ramping up
4.4
V
UVLO Hysterises-5V
0.3
V
Supply Current
Operating Supply Current
V12
6
mA
V5
30
Switching Controllers; Vcore (Vsen 1) and AGP (Vsen 2)
VID Section (Vcore only)
DAC output voltage (note 1)
0.99Vs Vs
1.01Vs V
DAC Output Line Regulation
0.1
%
DAC Output Temp Variation
0.5
%
VID Input LO
0.8
V
VID Input HI
2
V
VID input internal pull-up
resistor to V5
27
kΩ
Vsen2 Voltage
Select<0.8V
1.5
V
Select>2V
3.3
V
4-2
Rev. 1.3
12/8/00
US3021M
Error Comparator Section
Input bias current
Input Offset Voltage
Delay to Output
Current Limit Section
C.S Threshold Set Current
C.S Comp Offset Voltage
Hiccup Duty Cycle
Output Drivers Section
Rise Time
Fall Time
Dead band Time Between
High side and Synch Drive
(Vcore Switcher Only)
Oscillator Section (internal)
Osc Frequency
1.8V Regulator (Vsen 4)
Vsense Voltage
Vo4
Vsense Voltage
Input bias current
Output Drive Current
1.5V Regulator (Vsen 3)
Vsense Voltage
Vsense Voltage
Input bias current
Output Drive Current
Power Good Section
Vsen1 UV lower trip point
Vsen1 UV upper trip point
Vsen1 UV Hysterises
Vsen1 HV upper trip point
Vsen1 HV lower trip point
Vsen1 HV Hysterises
Vsen2 trip point
Vsen4 trip point
Vsen3 trip point
Power Good Output LO
Power Good Output HI
Fault (Overvoltage) Section
Core O.V. upper trip point
Core O.V. lower trip point
FAULT Output HI
Soft Start Section
Soft Start Current
Rev. 1.3
12/8/00
Vo3
-2
Vdiff=10mV
2
+2
100
uA
mV
nS
+5
200
Css=0.1 uF
10
uA
mV
%
CL=3000pF
CL=3000pF
70
70
nS
nS
CL=3000pF
200
nS
Rt=Open
217
Khz
Ta=25, Drive4 = Vsen4
1.800
1.800
V
V
uA
mA
-5
2
Vaux-Vdrive>0.6V
50
Ta=25, Drive3 = Vsen3
1.500
1.500
2
Vaux-Vdrive>0.6V
Vsen1 ramping down
Vsen1 ramping up
50
V
V
uA
mA
Select<0.8V
Select>2V
Fix=GND
Fix=Open
Fix=GND
Fix=Open
RL=3mA
RL=5K pull up to 5V
0.90Vs
0.92Vs
.02Vs
1.10Vs
1.08Vs
.02Vs
1.100
2.560
0.920
1.320
0.920
1.140
0.4
4.8
V
V
V
V
V
V
V
V
V
V
V
V
V
V
Vsen1 ramping up
Vsen1 ramping down
Io=3mA
1.17Vs
1.15Vs
10
V
V
V
OCset=0V , Phase=5V
20
uA
Vsen1 ramping up
Vsen1 ramping down
4-3
US3021M
Note 1: Vs refers to the set point voltage given in Table 1.
D4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
D3
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
D2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
D1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
D0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
Vs
1.30
1.35
1.40
1.45
1.50
1.55
1.60
1.65
1.70
1.75
1.80
1.85
1.90
1.95
2.00
2.05
D4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
D3
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
D2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
D1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
D0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
Vs
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
3.4
3.5
Table 1 - Set point voltage vs. VID codes
PIN DESCRIPTIONS
PIN# PIN SYMBOL
7
VID0
6
VID1
5
VID2
4
VID3
3
VID4
8
PGOOD
21
FB
1
9
Drive2
SD
4-4
Pin Description
LSB input to the DAC that programs the output voltage. This pin is TTL compatible that
realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by
a 27kΩ resistor to 5V supply.
Input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by a
27kΩ resistor to 5V supply.
Input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by a
27kΩ resistor to 5V supply.
MSB input to the DAC that programs the output voltage. This pin is TTL compatible that
realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by
a 27kΩ resistor to 5V supply.
This pin selects a range of output voltages for the DAC.When in the LOW state the range
is 1.3V to 2.05V and when it switches to HI state the range is 2.0V to 3.5V. This pin is
TTL compatible that realizes a logic “1” as either HI or Open. When left open,his pin is
pulled up internally by a 27kΩ resistor to 5V supply.
This pin is an open collector output that switches LO when any of the outputs are outside
of the specified under voltage trip point. It also switches low when Vsen1 pin is more than
10% above the DAC voltage setting.
This pin provides the feedback for the synchronous switching regulator. Typically this pin
can be connected directly to the output of the switching regulator. However, a resistor
divider is recommended to be connected from this pin to vout1 and GND to adjust the
output voltage for any drop in the output voltage that is caused by the trace resistance.
The value of the resistor connected from Vout1 to FB1 must be less than 1000Ω.
This pin controls the gate of an external MOSFET for the AGP linear regulator.
This pin provides shutdown for all the regulatos. A TTL compatible, logic level high applied
to this pin disables all the outputs and discharges the soft start capacitor. The SD signal
turns off the synchronous allowing body diode to conduct and discharge the output cap.
Rev. 1.3
12/8/00
US3021M
PIN# PIN SYMBOL
22
Vsen1
10
Vsen2
15
23
Drive4
OCSET
26
PHASE
12
SS
13
FAULT/Rt
18
19
16
Drive3
Vsen3
NC
14
17
24
Vsen4
GND
PGND
25
27
28
LGATE
UGATE
V12
20
V5
11
Select
2
Rev. 1.3
12/8/00
Pin Description
This pin is internally connected to the undervoltage and overvoltage comparators sensing
the Vcore status. It must be connected directly to the Vcore supply.
This pin provides the feedback for the AGP linear regulator. The Select pin when connected to the "Type Detect" pin of the AGP slot automatically selects the right voltage for
the AGP Vddq.
This pin controls the gate of an external MOSFET for the 1.8V chip set linear regulator.
This pin is connected to the Drain of the power MOSFET of the Core supply and it
provides the positive sensing for the internal current sensing circuitry. An external resistor programs the C.S threshold depending on the Rds of the power MOSFET. An external
capacitor is placed in parallel with the programming resistor to provide high frequency
noise filtering.
This pin is connected to the Source of the power MOSFET for the Core supply and it
provides the negative sensing for the internal current sensing circuitry.
This pin provides the soft start for all the regulators. An internal current source charges
an external capacitor that is connected from this pin to GND which ramps up the outputs
of the regulators, preventing the outputs from overshooting as well as limiting the input
current. The second function of the Soft Start cap is to provide long off time (HICCUP) for
the synchronous MOSFET during current limiting.
This pin has dual function. It acts as an output of the OVP circuitry or it can be used to
program the frequency using an external resistor . When used as a fault detector, if any
of the switcher outputs exceed the OVP trip point, the FAULT pin switches to 12V and
the soft start cap is discharged. If the FAULT pin is to be connected to any external
circuitry, it needs to be buffered.
This pin controls the gate of an external transistor for the 1.5V GTL+ linear regulator.
This pin provides the feedback for the linear regulator that its output drive is Drive3.
This pin is not connected internally.
This pin provides the feedback for the linear regulator that its output drive is Drive4.
This pin serves as the ground pin and must be connected directly to the ground plane.
This pin serves as the Power ground pin and must be connected directly to the GND
plane close to the source of the synchronous MOSFET. A high frequency capacitor
(typically 1 uF) must be connected from V12 pin to this pin for noise free operation.
Output driver for the synchronous power MOSFET for the Core supply.
Output driver for the high side power MOSFET for the Core supply.
This pin is connected to the 12 V supply and serves as the power Vcc pin for the output
drivers. A high frequency capacitor (typically 1 uF) must be placed close to this pin and
PGND pin and be connected directly from this pin to the GND plane for the noise free
operation.
5V supply voltage. A high frequency capacitor (0.1 to 1 uF) must be placed close to this
pin and connected from this pin to the GND plane for noise free operation.
This pin provides automatic voltage selection for the AGP switching regulator. When it is
pulled LO, the voltage is 1.5V and when left open or pulled to HI, the voltage is 3.3V.
Leaving this pin open provides fixed output voltages of the 1.5V and 1.8V for the #3 and #4
linear regulators. When this pin is grounded the reference to the linear regulators are set
to 1.26V and therefore the output of the regulators can be programmed to any voltages
above the 1.26V using; Vout=1.26*(1+Rtop/Rbot)
Where:
Rtop=Top resistor connected from the output to the Vsense pin
Rbot=Bottom resistor connected from the Vsense pin to ground.
4-5
US3021M
BLOCK DIAGRAM
V12
V5
SD
Fb
Enable
UVLO
1.17Vset
V12
Over
Voltage
Vsen1
PGood
Vsen3
Vsen4
Vset
UGate
Enable
PWM
Control
+
1.1Vset
V12
Slope
Comp
LGate
Osc
Phase
Fix
0.9Vset
Enable
Soft
Start &
Fault
Logic
OCSet
Over
Current
PGnd
200uA
Gnd
Drive4
Fault / Rt
R
SS
1.26V
3R
Vset
Drive3
VID0
Select
VID1
1.5V
3.3V
R
5Bit
DAC
VID2
VID3
3R
VID4
Drive2
Vsen2
3021Mblk1-1.0
Figure 1 - Simplified block diagram of the US3021M.
4-6
Rev. 1.3
12/8/00
US3021M
TYPICAL APPLICATION
(Dual Layout with HIP6021)
R1
12V
L1
C5
5V
C1
R2
C4
23
OCSET
R4
C3
C2
28
V12
9 SD
Q1
UGATE 27
2 FIX
L2
11 SELECT
Type Detect
PHASE 26
Vcore
C7
R7
Q3
LGATE 25
C22
R3
R6
R14
R5
16 NC
(Vaux)
3.3Vin
C6
Q2
R10
PGND 24
VSEN1 22
1 DRIVE2
FB 21
R9
10 VSEN2
Vout2
1.5V / 3.3V
U1
V5 20
(COMP)
C13
C15
C16
C17
R8
C14
R11
R12
VID0 7
Q4
18 DRIVE3
VID1 6
VID2 5
19 VSEN3
Vout3
1.5V
VID3 4
VID4 3
C18
Vcc3
R13
PGOOD 8
Q5
15 DRIVE4
FAULT/RT 13
VSEN4 GND
14
17
PGood
C21
SS
12
3021Mapp2-1.2
Vout4
1.8V
C20
C19
Figure 2 - Typical application of US3021M in a dual layout with HIP6021 for an on board DC-DC converter
providing power for the Vcore , GTL+, 1.8V chip set supply as well as auto select AGP supply for the next
generation PC applications.
Part#
HIP6021
US3021M
R3
O
S
R5
S
O
S - Short
O - Open
R9
O
S
R12
V
O
C15
O
V
C16
V
O
C17
V
O
V - See Unisem or Harris parts list for the value.
Table 2 - Dual layout component table
Rev. 1.3
12/8/00
4-7
US3021M
US3021M Application Parts List
Dual Layout with HIP6021
Ref Desig
Q1
Q2
Q3
Q4,5
L1
Description
MOSFET
MOSFET
MOSFET with Schottky
MOSFET
Inductor
Qty
1
1
1
2
1
L2
Inductor
1
C1
C2,3
C4
C5
C6,18
C7
C13,19
C14,15
C16,17
Capacitor, Electrolytic
Capacitor, Electrolytic
Capacitor, Ceramic
Capacitor, Ceramic
Capacitor, Electrolytic
Capacitor, Electrolytic
Capacitor, Electrolytic
Capacitor, Ceramic
Capacitor, Ceramic
1
2
1
1
2
6
1
2
2
C20,21
C22
R1
R2
R3,5,12
Capacitor, Ceramic
Capacitor, Ceramic
Resistor
Resistor
Resistor
2
1
1
1
3
R4,7,14
R6,8,10
R9
R11
R13
Resistor
Resistor
Resistor
Resistor
Resistor
3
3
1
1
1
4-8
Part #
IRL3103S, TO263 package
IRLR3103, TO252 package
IRL3103D1S, TO263 package
IRLR024, TO252 package
L=1uH, 5052 core with 4 turns of
1.0mm wire
L=2.7uH, 5052B core with 7 turns of
1.2mm wire
10MV470GX, 470uF,10V
10MV1200GX, 1200uF,10V
220pF, 0603
1uF, 0805
6MV1000GX, 1000uF,6.3V
6MV1500GX, 1500uF,6.3V,
6MV1500GX, 1500uF,6.3V,
1uF, 0603
See Table 2, dual layout component
0603 * 2
0.1uF, 0603
1000pF, 0603
10Ω, 5%, 0603
3.3kΩ, 5%, 0603
See Table 2, dual layout component
0603 * 3
4.7Ω, 5%, 1206
2.2kΩ, 1%, 0603
0Ω, 0603
220kΩ, 1%, 0603
10kΩ, 5%, 0603
Manuf
IR
IR
IR
IR
Micro Metal
Micro Metal
Sanyo
Sanyo
Sanyo
Sanyo
Sanyo
Rev. 1.3
12/8/00