Datasheet US3021MCW Datasheet (UNISEM)

Page 1
5 BIT PROGRAMMABLE SYNCHRONOUS BUCK
FEATURESFEATURES
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
APPLICATIONSAPPLICATIONS
Total Power Soloution for Next Generation Intel Processor application
US3021M
PLUS TRIPPLE LDO CONTROLLER
PRELIMINARY DATASHEET
DESCRIPTIONDESCRIPTION
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 control-
ler 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 cur-
rent 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 win-
dow comparator that switches its open collector output low when any one of the outputs is outside of a pre pro­grammed window.
TYPICAL APPLICATIONTYPICAL APPLICATION
5V
3.3V
Vout2
Vout3
LINEAR
CONTROL
US3021M
LINEAR
CONTROL
PACKAGE ORDER INFORMATIONPACKAGE ORDER INFORMATION
Ta (°C) Device Package
0 TO 70 US3021MCW 28 pin Plastic SOIC WB
Rev. 1.3 12/8/00
SWITCHER
CONTROL
LINEAR
CONTROL
3021Mapp3-1.1
Vout1
Vout4
4-1
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US3021M
ABSOLUTE MAXIMUM RATINGSABSOLUTE 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 INFORMATIONPACKAGE INFORMATION
28 PIN WIDE BODY PLASTIC SOIC (W)
TOP VIEW
1
Drive2
2
Fix
3
VID4
4
VID3
5
VID2
6
VID1
7
VID0
8 21
PGood
9 20
SD
10 19
Vsen2
11 18
Select
12 17
SS
13 16
Fault / Rt
14
Vsen4 Drive4
28 27 26 25 24 23 22
15
V12 UGate Phase LGate PGnd OCSet Vsen1 Fb V5 Vsen3 Drive3 Gnd NC
θJA =80°C/W
ELECTRICAL SPECIFICATIONSELECTRICAL 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 k Vsen2 Voltage Select<0.8V 1.5 V
Select>2V 3.3 V
4-2
Rev. 1.3
12/8/00
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US3021M
Error Comparator Section
Input bias current 2 uA Input Offset Voltage -2 +2 mV Delay to Output Vdiff=10mV 100 nS
Current Limit Section
C.S Threshold Set Current 200 uA C.S Comp Offset Voltage -5 +5 mV Hiccup Duty Cycle Css=0.1 uF 10 %
Output Drivers Section
Rise Time CL=3000pF 70 nS Fall Time CL=3000pF 70 nS Dead band Time Between High side and Synch Drive (Vcore Switcher Only) CL=3000pF 200 nS
Oscillator Section (internal)
Osc Frequency Rt=Open 217 Khz
1.8V Regulator (Vsen 4)
Vsense Voltage Vo4 Ta=25, Drive4 = Vsen4 1.800 V Vsense Voltage 1.800 V Input bias current 2 uA Output Drive Current Vaux-Vdrive>0.6V 50 mA
1.5V Regulator (Vsen 3)
Vsense Voltage Vo3 Ta=25, Drive3 = Vsen3 1.500 V Vsense Voltage 1.500 V Input bias current 2 uA Output Drive Current Vaux-Vdrive>0.6V 50 mA
Power Good Section
Vsen1 UV lower trip point Vsen1 ramping down 0.90Vs V Vsen1 UV upper trip point Vsen1 ramping up 0.92Vs V Vsen1 UV Hysterises .02Vs V Vsen1 HV upper trip point Vsen1 ramping up 1.10Vs V Vsen1 HV lower trip point Vsen1 ramping down 1.08Vs V Vsen1 HV Hysterises .02Vs V Vsen2 trip point Select<0.8V 1.100 V
Select>2V 2.560 V
Vsen4 trip point Fix=GND 0.920 V
Fix=Open 1.320 V
Vsen3 trip point Fix=GND 0.920 V
Fix=Open 1.140 V Power Good Output LO RL=3mA 0.4 V Power Good Output HI RL=5K pull up to 5V 4.8 V
Fault (Overvoltage) Section
Core O.V. upper trip point Vsen1 ramping up 1.17Vs V Core O.V. lower trip point Vsen1 ramping down 1.15Vs V FAULT Output HI Io=3mA 10 V
Soft Start Section
Soft Start Current OCset=0V , Phase=5V 20 uA
Rev. 1.3 12/8/00
4-3
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US3021M
Note 1: Vs refers to the set point voltage given in Table 1.
D4 D3 D2 D1 D0 Vs D4 D3 D2 D1 D0 Vs
0 1 1 1 1 1.30 1 1 1 1 1 2.0 0 1 1 1 0 1.35 1 1 1 1 0 2.1 0 1 1 0 1 1.40 1 1 1 0 1 2.2 0 1 1 0 0 1.45 1 1 1 0 0 2.3 0 1 0 1 1 1.50 1 1 0 1 1 2.4 0 1 0 1 0 1.55 1 1 0 1 0 2.5 0 1 0 0 1 1.60 1 1 0 0 1 2.6 0 1 0 0 0 1.65 1 1 0 0 0 2.7 0 0 1 1 1 1.70 1 0 1 1 1 2.8 0 0 1 1 0 1.75 1 0 1 1 0 2.9 0 0 1 0 1 1.80 1 0 1 0 1 3.0 0 0 1 0 0 1.85 1 0 1 0 0 3.1 0 0 0 1 1 1.90 1 0 0 1 1 3.2 0 0 0 1 0 1.95 1 0 0 1 0 3.3 0 0 0 0 1 2.00 1 0 0 0 1 3.4 0 0 0 0 0 2.05 1 0 0 0 0 3.5
Table 1 - Set point voltage vs. VID codes
PIN DESCRIPTIONSPIN DESCRIPTIONS
PIN# PIN SYMBOL
7 VID0
6 VID1
5 VID2
4 VID3
3 VID4
8 PGOOD
21 FB
1 Drive2 9 SD
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 27k 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 27k 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 27k 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 27k 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 27k 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.
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Rev. 1.3
12/8/00
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US3021M
PIN# PIN SYMBOL
22 Vsen1 10 Vsen2
15 Drive4 23 OCSET
26 PHASE 12 SS
13 FAULT/Rt
18 Drive3 19 Vsen3 16 NC
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.
14 Vsen4 17 GND 24 PGND
25 LGATE 27 UGATE 28 V12
20 V5 11 Select 2
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.
Rev. 1.3 12/8/00
4-5
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US3021M
BLOCK DIAGRAMBLOCK DIAGRAM
V12
V5
SD
Vsen1
PGood
Vsen3 Vsen4
Fix
Drive4
Drive3
Select
Drive2
Vsen2
UVLO
1.26V
Enable
Fb
1.17Vset Over
Voltage
Vset
Enable
V12
UGate
PWM
1.1Vset
+
Slope Comp
Osc
Control
V12
LGate
Phase
Soft
0.9Vset
Enable
Start &
Fault
Logic
R
3R
Over
Current
200uA
Vset
OCSet PGnd Gnd Fault / Rt SS
VID0
1.5V
R
3R
3.3V
5Bit
DAC
3021Mblk1-1.0
VID1 VID2 VID3 VID4
4-6
Figure 1 - Simplified block diagram of the US3021M.
Rev. 1.3
12/8/00
Page 7
TYPICAL APPLICATIONTYPICAL APPLICATION
(Dual Layout with HIP6021)
US3021M
12V
Type Detect
3.3Vin
Vout2
1.5V / 3.3V
Vout3
1.5V
Vout4
1.8V
R1
L1
5V
C1
C6
C2
R3
R5
Q2
C13
Q4
C18
Q5
3021Mapp2-1.2
C19
28
V12
SD
9
FIX2 SELECT
11
NC
16
(Vaux)
DRIVE2
1
VSEN210
DRIVE3
18
VSEN3
19
DRIVE4
15
VSEN4 GND
U1
1714
23
OCSET
UGATE 27
PHASE
LGATE
PGND
VSEN1
(COMP)
VID0 VID1 VID2 VID3 VID4 3
PGOOD 8
FAULT/RT
SS
12
R4
26
R7
25
24 22 21
FB
R9
V5
20
C15
7 6 5 4
13
C20
C17
Q1
Q3 C22
C16
R12
Vcc3
R14
R8
C3C4R2C5
L2
Vcore
C7
R6 R10
C14
R11
R13
PGood
C21
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# R3 R5 R9 R12 C15 C16 C17 HIP6021 O S O V O V V US3021M S O S O V O O
S - Short O - Open V - See Unisem or Harris parts list for the value. Table 2 - Dual layout component table
Rev. 1.3 12/8/00
4-7
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US3021M
US3021M Application Parts List Dual Layout with HIP6021
Ref Desig Description Qty Part # Manuf Q1 MOSFET 1 IRL3103S, TO263 package IR Q2 MOSFET 1 IRLR3103, TO252 package IR Q3 MOSFET with Schottky 1 IRL3103D1S, TO263 package IR Q4,5 MOSFET 2 IRLR024, TO252 package IR L1 Inductor 1 L=1uH, 5052 core with 4 turns of Micro Metal
1.0mm wire
L2 Inductor 1 L=2.7uH, 5052B core with 7 turns of Micro Metal
1.2mm wire C1 Capacitor, Electrolytic 1 10MV470GX, 470uF,10V Sanyo C2,3 Capacitor, Electrolytic 2 10MV1200GX, 1200uF,10V Sanyo C4 Capacitor, Ceramic 1 220pF, 0603 C5 Capacitor, Ceramic 1 1uF, 0805 C6,18 Capacitor, Electrolytic 2 6MV1000GX, 1000uF,6.3V Sanyo C7 Capacitor, Electrolytic 6 6MV1500GX, 1500uF,6.3V, Sanyo C13,19 Capacitor, Electrolytic 1 6MV1500GX, 1500uF,6.3V, Sanyo C14,15 Capacitor, Ceramic 2 1uF, 0603 C16,17 Capacitor, Ceramic 2 See Table 2, dual layout component
0603 * 2 C20,21 Capacitor, Ceramic 2 0.1uF, 0603 C22 Capacitor, Ceramic 1 1000pF, 0603 R1 Resistor 1 10, 5%, 0603 R2 Resistor 1 3.3k, 5%, 0603 R3,5,12 Resistor 3 See Table 2, dual layout component
0603 * 3 R4,7,14 Resistor 3 4.7, 5%, 1206 R6,8,10 Resistor 3 2.2k, 1%, 0603 R9 Resistor 1 0, 0603 R11 Resistor 1 220k, 1%, 0603 R13 Resistor 1 10k, 5%, 0603
4-8
Rev. 1.3
12/8/00
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