SEMTECH SC2642TSTR

SC2642
Multi-Platform
Two-Phase PWM Controller
POWER MANAGEMENT
Description
The VID structure of the SC2642 supports VID-on-Fly applications for any platform. The cycle-by-cycle current limit
plus the intelligent over current shut down provide the
maximum versatility of the system without false tripping
under all possible changes of VID and load conditions.
The differential voltage feedback sense eliminates the
error caused by high load current on the ground plane.
External offset is easy to achieve for any platforms and
the VID settings. The enable function is also provided to
interface with the corresponding system signal for correct
start up timing and shut down timing.
The SC2642 provides microprocessor core voltage
regulation solution with two paralleled PWM channels.
Multi-phase buck regulator utilizes the phase-shift timing control to allow interleaved switching of the power
switches. This architecture minimizes the core voltage
ripple and the input current ripple, which leads to optimized voltage regulator design for power density, transient responses, and the thermal performances.
To satisfy the highly dynamic nature of the modern
microprocessors, the SC2642 adopts peak current mode
control topology which ensures wide control loop
bandwidth and fast transient responses. The current mode
control provides intrinsic phase current matching. The
maximum ripple frequency is greater than 1MHz.
Features
!
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One of the outstanding features of the SC2642 is its voltage regulation accuracy. Not only it provides better than
1% set point accuracy, but also the accuracy to fully complaint with the stringent load line slope specifications
mandated by the modern microprocessors.Lossless output current sensing ensures the regulator output voltage
is accurately positioned according to the load current condition, and an internal temperature compensation technology further enhances the performance of voltage accuracy.
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The patented Combi-SenseTM topology is employed by
SC2642. The MOSFET Rds(on) and the output inductor
winding resistance are used to generate the phase current information. The Combi-SenseTM MOSFET driver plus
the SC2642 enables the complete solution.
!
!
!
The SC2642 is a multi-platform controller. It conforms to
Intel VRM/VRD10.0, VRM9.X, and AMD K-8 (OpteronTM)
VID specifications. With very minor changes of the schematic and the layout, the SC2642 based solution can be
ported form one platform to another. This greatly benefits the system manufactures for reductions of design
cycle and minimize the inventory management.
April 22, 2005
VRD/VRM10.0, VRM9.X, and K-8 compliant
Core Voltage Set Point Accuracy 0.5%
Combi-SenseTM Current Mode Control
Intrinsic Phase Current Matching
Fast Transient Responses
Active Droop with Temperature Compensation to Meet
Load Line Slope
Support VID-on-Fly with 5 or 6 bit VID
Enable Function for Power Sequencing
Cycle-by-Cycle Peak Current Limit
Intelligent Over Current Shut Down
Over Voltage Protection When Using Semtech
Combi-SenseTM Driver SC1211
Under Voltage Protection Built in
External programmable Soft-Start
Externally programmable switching frequency (up to
1MHz output ripple frequency)
Applications
!
!
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1
Voltage Regulator VRD10.x
Voltage Regulator VRM9.X
Voltage Regulator K-8
High Current, Low Voltage Step Down DC/DC
Converters
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SC2642
POWER MANAGEMENT
Typical Application Circuit
ATX12V
1
C5
1800uF/16V
+
L2
1
L1
640nH
C15
4.7uF/1206
C7
PN2
IR0
R3
C9
2.2nF
R14
1.5K
2
M1
VIN
M5
VPN1
R8
C18
1uF
R11
10
R18
R15
C19
V_COREV_CORE+
M2
M6
C16
C20
0.1uF
VCC
C3
1nF
100
R2
VPN2
R5
C14
1R0
R9
OS2
VID3
VID4
VCC
DACSTEP
FB
GNDSEN
ERROUT
BGOUT
OS1
C17
20
9
8
7
6
5
4
3
2
1
R12
VPN2
C21
4.7uF
C11
C1
4.7uF
VIN
D2
U2
OUT2
OUT1
AGND
OSCREF
VID5
PGOOD
VID0
VID1
VID2
10
11
12
14
13
15
16
17
18
19
1uF D1N4148
R10
VOUT
8
OUTSEN
R13
SC2642
6
ATX12V
C4
2
Note (1)
+
1800uF/16V
VOUT
VRM_EN
R17
OFFSET-
(Ope n Col lector/Drai n Input, No Pull -u p)
VCC
R16
OFFSET+
ATX12V
Use the same power
source as FET driver
DIFFERENTIAL PAIR
FOR REMOTE SENSE
Note (2)
SC1214
Notes:
(1) Output filter design: Please follow guidelines issued by Intel  and AMD .
(2) Please follow the guidelines issued by Intel  and AMD.
D1
D1N4148
VIN
ROSC1
C2
1R0
R1
C12
4.7uF
R6
100
C13
1nF
VPN1
U1
1uF
D RN1
PGN D
2
TG1
M3
M7
VIN
M4
M8
R7
0R0
C8
4.7uF/1206
PN1
R4
IR0
C10
2.2nF
Pull-up Voltage
VR10: 2V
VRM9.x: 5V
K-8: 12V
+
L3
1800uF/16V
C6
1
2
VOUT
+ COUT1
PGND
Note (1)
VID5
VID0
VID1
VID2
VID3
VID4
Note (2)
PWRGOOD (Open Collector Output)
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2
 2005 Semtech Corp.
BST1
VREG1
1
20
BG1
19
CO1
4
VIN1
17
NC
3
18
VIN2
CO2
5
VPN 1
16
VPN2
NC
15
BG2
TG2
7
14
VR EG2
BST2
13
10
PGND
9
12
DR N2
11
SC2642
POWER MANAGEMENT
Absolute Maximum Ratings
Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical
Characteristics section is not implied.
Parameter
Symbol
Maximum
Units
VCC
20
V
Combi-Sense/Direct Output Voltage
OS1, OS2, OUTSEN
5
V
VID pins except VID5,Frequency pin
VID0 ~ VID4,OSCREF
7
V
GSENSE
-0.3 to 0.3
V
Vcc + 0.3
V
Supply Voltage
Ground sense
All other pins
Ambient Temperature Range
TA
0 to 105
o
Junction Temperature Range
TJ
0 to 125
o
Storage Temperature Range
TSTG
-65 to +150
o
Lead Temperature (Soldering) 10 Sec.
TLEAD
260
o
C
C
C
C
Electrical Characteristics
o
Unless specified: VCC = 12V, VID=1.50V (101110,VRD10), FOSC = 200kHz/phase, TA = 27 C. See Typical Application Circuit.
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
7.5
12
14
V
10
13
mA
7.3
7.5
V
Chip_Supply
IC Supply Voltage
VCC
IC Supply Current
ICC
UVLO Ramp Up
UVLO Ramp Down
6.4
6.6
V
2.945
2.990
3.035
V
220
300
330
µA
Reference Section
Bandgap Output
VBGOUT
CBGOUT = 4.7nF
Source Current
VCC = 10.0V ~ 14.0V
0.5
mV/V
0oC < TA < 85oC
1
%
VID Step
VRM9.X, K-8, LSB
25
mV
VID Step
VRD/VRM10, LSB
12.5
mV
Supply Rejection
Temperature Stability
Voltage Accuracy
VOUT
VRD10 ; Internal offset=-20mV
-0.5
+0.5
%
VRM9.x ; Internal offset=-20mV
-1
+1
%
K-8 ; Internal offset=+25mV
-1
+1
%
220
kHz
500
kHz
Oscillator Section
Switching Frequency
Switching Frequency Range
Temperature Stability
ROSC = 230K / Per phase
180
Per phase
100
0oC < TA < 85oC
200
+/ - 5
%
NOTE : 1) Guaranteed by design, not tested in production. Specifications subject to change without notice.
 2005 Semtech Corp.
3
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SC2642
POWER MANAGEMENT
Electrical Characteristics (Cont.)
o
Unless specified: VCC = 12V, VID=1.50V (101110,VRD10), FOSC = 200kHz/phase, TA = 27 C. See Typical Application Circuit.
Parameter
Test Conditions
Min
Typ
Max
Units
Voltage Error Amplifier
Input Offset Voltage
+/ - 3
mV
25
nA
1V < VERROUT < 4V
80
dB
CERROUT = 10pF
10
MHz
Slew Rate
10
V/µS
Transconductance Gain
0.5
mA/V
Clamp level for OCP
4.4
V
Input Bias Current
Open Loop Gain
Unity Gain Bandwidth
Clamp level Accuracy
-8
+8
%
Current Sense Amplifiers
Input Offset Voltage
+/ - 3
mV
Input Bias Current
50
nA
Gain
10
V/V
80
dB
CMRR
0 to 3V
Input Common Mode Range
-0.3
3
V
Gain Match
2
%
Bandwidth
6
MHz
5.4
V/V
+/ - 5
%
Droop Amplifier
Gain
Gain Accuracy(1)
VIDs
Input low voltage threshold
[VID0:5]
Input high voltage threshold
[VID0:5]
1.8
[VID0:4] = 0V
120
VID5 pull up voltage for VRD/VRM10
VID5
VID5 pull up voltage for VRM9.X
VID5 pull up voltage for K-8
Bias current
1.2
V
V
185
250
uA
1.8
2.5
V
VID5
4
6
V
VID5
8
VCC
V
Threshold Rising
VID - Power Good Threshold
250
400
mV
Threshold Falling
VID - Power Good Threshold
575
mV
Pwrgood = VCC
100
nA
Power Good
Output High Leakage
Output Low Sink
Pwrgood = 0.8V
2
VID - Shut Down Threshold
550
350
mA
Current Limit Section
Shutdown Voltage
650
750
mV
NOTE : 1) Guaranteed by design, not tested in production. Specifications subject to change without notice.
 2005 Semtech Corp.
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SC2642
POWER MANAGEMENT
Pin Configurations
Ordering Information
Top View
Part Number
(1)
SC2642TSTR
SC2642TSTRT(1)(2)
Package
Temp. Range (TJ)
TSSOP-20
0 to 125 OC
TSSOP-20
0 to 125 OC
SC2642EVB
Evaluation Board
Note:
(1) Only available in tape and reel packaging. A reel contains 2500 devices.
(2) Lead free package. Device is fully WEEE and RoHS compliant.
(20-Pin TSSOP)
Pin Descriptions
Pin#
Pin Name
1
OS1
2
BGOUT
BG reference pin. Connect soft start cap to AGND.
3
ERROUT
Error-amplifier output. Connect compensation network to AGND.
4
GSENSE
Remote sense for GND. Rout with FB trace as a differnetial pair to the CPU socket.
5
FB
6
DACSTEP
7
VCC
Power supply for chip.
8
VID4
VID MSB.
9
VID3
10
VID2
11
VID1
12
VID0
VID LSB.
13
VID5
12.5mV bit for VR10. VID5 pull-up to VCC for K-8; VID5 pull-up to 5V for VRM9.X.
14
PGOOD
Power good. Open Collect output.
15
OSCREF
Oscillator frequency setting. Connect a resistor to AGND.
16
AGND
Clean ground for analog signals.
17
OUT1
PWM output1.
18
OUT2
PWM output2.
19
OUTSEN
20
OS2
 2005 Semtech Corp.
Pin Function
Current sense input 1.
Feedback pin.
VID step speed setting. Connect a cap to AGND to program the DAC slew rate.
Direct output sense.
Current sense input 2.
5
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SC2642
POWER MANAGEMENT
Block Diagram
C/A1
OS1
+
1
OUT
+
-
OUT
C/A2
OS2
20
DRV1
PWM1
R
17
OUT1
18
OUT2
S
-
+
+
OUT
DRV2
PWM2
OUT
-
OUTSEN
R
OUTSEN
Q
Q
S
19
Errout
OSCILLATOR
Ramp
OSCREF
15
VID0
12
CLOCK DIVIDER
ROSC
OSC
VID2
10
VID3
9
VID0
VID1
VID2
VID3
VID4
VID5
Shut D ow n
11
P1
P2
11111
INHIBIT
DAC
VID1
CLK
2R
VDAC
-
2R
OUT
+
VID4
8
VID5
13
DACSTEP
6
R
VBG
PWR_GOOD
+
14
PGOOD
3
ERROUT
7
VCC
16
AGND
OUT
OUTSEN
DROOP
Power Good Threshold
R
+
-
0
OUT
-
FB
-
5
R
R
E/A
ERROUT
OUT
+
OCP &
SHUTDOWM
R
BGOUT
BGOUT
2
-
0
OUT
BUFFER
+
VCC
BANDGAP
VCC
GSENSE
4
 2005 Semtech Corp.
UVLO &
LATCH
VREF
GSEN
VBG
6
BGOUT
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SC2642
POWER MANAGEMENT
Applications Information- Output Voltage
VRM9.X Output Voltage
Unless specified: 0 = GND; 1 = High (or Floating). TA = 25oC, VCC = 12V
VID4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
 2005 Semtech Corp.
VID3
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
VID2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
VID1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
7
VID0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
Vout
(V)
OFF
1.1
1.125
1.15
1.175
1.2
1.225
1.25
1.275
1.3
1.325
1.35
1.375
1.4
1.425
1.45
1.475
1.5
1.525
1.55
1.575
1.6
1.625
1.65
1.675
1.7
1.725
1.75
1.775
1.8
1.825
1.85
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SC2642
POWER MANAGEMENT
Applications Information- Output Voltage (Cont)
VR D 10 Output Voltage
Unless speci fi ed: 0 = GND ; 1 = Hi gh. TA = 25oC , VCC = 12V
VID 5
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
 2005 Semtech Corp.
VID 4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
VID 3
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
VID 2
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
8
VID 1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
VID 0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
Vout
(V)
0.8375
0.8500
0.8625
0.8750
0.8875
0.9000
0.9125
0.9250
0.9375
0.9500
0.9625
0.9750
0.9875
1.0000
1.0125
1.0250
1.0375
1.0500
1.0625
1.0750
1.0875
OFF
OFF
1.1000
1.1125
1.1250
1.1375
1.1500
1.1625
1.1750
1.1875
1.2000
1.2125
1.2250
1.2375
1.2500
1.2625
1.2750
1.2875
1.3000
1.3125
1.3250
1.3375
1.3500
1.3625
1.3750
1.3875
1.4000
1.4125
1.4250
1.4375
1.4500
1.4625
1.4750
1.4875
1.5000
1.5125
1.5250
1.5375
1.5500
1.5625
1.5750
1.5875
1.6000
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SC2642
POWER MANAGEMENT
Applications Information- Output Voltage (Cont)
K -8 Output Voltage
Unless speci fi ed: 0 = GND ; 1 = Hi gh (or Floati ng). TA = 25oC , VCC = 12V
VID 4
VID 3
VID 2
VID 1
VID 0
VOUT (V)
0
0
0
0
0
1.550
0
0
0
0
1
1.525
0
0
0
1
0
1.500
0
0
0
1
1
1.475
0
0
1
0
0
1.450
0
0
1
0
1
1.425
0
0
1
1
0
1.400
0
0
1
1
1
1.375
0
1
0
0
0
1.350
0
1
0
0
1
1.325
0
1
0
1
0
1.300
0
1
0
1
1
1.275
0
1
1
0
0
1.250
0
1
1
0
1
1.225
0
1
1
1
0
1.200
0
1
1
1
1
1.175
1
0
0
0
0
1.150
1
0
0
0
1
1.125
1
0
0
1
0
1.100
1
0
0
1
1
1.075
1
0
1
0
0
1.050
1
0
1
0
1
1.025
1
0
1
1
0
1.000
1
0
1
1
1
0.975
1
1
0
0
0
0.950
1
1
0
0
1
0.925
1
1
0
1
0
0.900
1
1
0
1
1
0.875
1
1
1
0
0
0.850
1
1
1
0
1
0.825
1
1
1
1
0
0.800
1
1
1
1
1
OFF
 2005 Semtech Corp.
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SC2642
POWER MANAGEMENT
Outline Drawing - TSSOP-20
A
D IM
D
e
A
A1
A2
b
c
D
E1
E
e
L
L1
N
01
aaa
bbb
ccc
N
2X
E /2
E1
E
P IN 1
IN D IC A T O R
ccc C
2 X N /2 T IP S
1 2 3
e /2
B
aaa
S E A T IN G
P LA N E
D IM E N S IO N S
M IL L IM E T E R S
IN C H E S
M I N N O M M A X M IN N O M M A X
.0 0 2
.0 3 1
.0 0 7
.0 0 3
.2 5 1
.1 6 9
.0 4 7
.0 0 6
.0 4 2
.0 1 2
.0 0 7
.2 5 9
.2 5 5
.1 7 7
.1 7 3
.2 5 2 B S C
.0 2 6 B S C
.0 3 0
.0 1 8
.0 2 4
(.0 3 9 )
20
0°
8°
.0 0 4
.0 0 4
.0 0 8
0 .0 5
0 .8 0
0 .1 9
0 .0 9
6 .4 0
4 .3 0
1 .2 0
0 .1 5
1 .0 5
0 .3 0
0 .2 0
6 .5 0
6 .6 0
4 .4 0
4 .5 0
6 .4 0 B S C
0 .6 5 B S C
0 .4 5
0 .6 0
0 .7 5
(1 .0 )
20
8°
0°
0 .1 0
0 .1 0
0 .2 0
D
C
A2
C
A
H
A1
bxN
bbb
C
A -B
D
c
GAGE
PLANE
0 .2 5
L
01
(L 1 )
S E E D E T A IL
S ID E V IE W
D E T A IL
A
A
NOTES:
1.
C O N T R O L L IN G D IM E N S IO N S A R E IN M IL L IM E T E R S ( A N G L E S IN D E G R E E S ).
2.
DATUM S
3.
D IM E N S IO N S "E 1 " A N D "D " D O N O T IN C L U D E M O L D F L A S H , P R O T R U S IO N S
OR G ATE BURRS.
4.
R E F E R E N C E J E D E C S T D M O - 1 5 3 , V A R IA T IO N A C .
-A -
AND
-B -
T O B E D E T E R M IN E D A T D A T U M P L A N E
-H -
Land Pattern - TSSOP-20
X
D IM
(C )
G
C
G
P
X
Y
Z
Z
Y
D IM E N S IO N S
IN C H E S
M I L L IM E T E R S
(.2 2 2 )
.1 6 1
.0 2 6
.0 1 6
.0 6 1
.2 8 3
(5 .6 5 )
4 .1 0
0 .6 5
0 .4 0
1 .5 5
7 .2 0
P
NOTES:
1.
T H IS L A N D P A T T E R N IS F O R R E F E R E N C E P U R P O S E S O N L Y .
C O N S U L T Y O U R M A N U F A C T U R IN G G R O U P T O E N S U R E Y O U R
C O M P A N Y 'S M A N U F A C T U R I N G G U I D E L I N E S A R E M E T .
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Rd., Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
 2005 Semtech Corp.
10
www.semtech.com