Transcript
SC2646B
Combi-Sense POWER MANAGEMENT Description
TM
2, 3 or 4 Phase PWM Controller
Features
e t e l o s b e O t e l o s b O
The SC2646B controller provides a microprocessor core voltage regulation solution for up to 4 paralleled PWM channels. The solution can be configured in 2, 3, or 4phase form. This multi-phase buck regulator utilizes phase-shift timing control to allow interleaved switching of the power switches. The product’s architecture minimizes the core voltage ripple and the input current ripple, which leads to optimized voltage regulator design for power density, transient responses, and thermal performances.
To satisfy the highly dynamic nature of the modern microprocessors, the SC2646B 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 2MHz.
One of the outstanding features of the SC2646B device is its voltage regulation accuracy. Not only does it provide 0.5% set point accuracy, but also the accuracy to be fully compliant with 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.
VRD/VRM10.X compliant Core Voltage Set Point Accuracy 0.5% Combi-SenseTM Current Mode Control Intrinsic Phase Current Matching Fast Transient Responses Active Droop to Meet Load Line Slope 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 Externally Programmable Soft-Start Externally Programmable Switching Frequency 2, 3, or 4-Phase Configurations 24-Pin TSSOP Package
Combi-SenseTM is a Trademark of Semtech Corporation
Applications
e t e l o s b e O t e l o s b O Voltage Regulator VRD/VRM10.X Voltage Regulation Modules High Current, Low Voltage Step Down DC/DC Converters
Semtech’s patented Combi-SenseTM topology is employed by SC2646B controller. The MOSFET Rds(on) and the output inductor winding resistance is used to generate the phase current information. Semtech’s SC1211 Combi-SenseTM MOSFET driver works with the SC2646B to enable a complete solution.
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 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.
Revision: Apr. 11, 2005
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SC2646B POWER MANAGEMENT Typical Application Circuit
ATX12V
ATX12V
AUX1
R2 44.2K
1
L1
2
AUX3
C9 6.8nF
VIN
R4 44.2K
R11 54.9K
PN2
R5 TBD
C10
TBD
20
21
22
23
24
PN1
OS4
MSENSE
OS3
OUTSEN
U2
OS2
OUT3
OUT4
BGOUT
OUT2
OS1
ERROUT
PN3
R6 TBD
R13 TBD
VOUT
R17
R7 TBD
VCC
PN2
PN3
2R2
R1
AUX3
AUX2
C6
1nF
R14
100
C23
1nF
D1N4148
D1
1uF
C3
C14
1uF
D1N4148
D2
C28
1uF
D1N4148
D3
1uF
C16
4.7uF
C15
PGND
1
640nH
R3 44.2K
R10 54.9K
AUX2
C8 6.8nF
1
2
3
4
5
19
320K
18
17
DRN
C37
1uF
PGND
C29
4.7uF
C30
1uF
PGND
C38
4.7uF
U1
9
9
U3
9
U4
R8
1
R18
1
R28
1
M2
M5
M8
M4
M1
M3
VIN
M6
VIN
M7
M9
C2 4.7uF/1206
PN3
R12
IR0
C12
2.2nF
PN2
C19 4.7uF/1206
R19
IR0
C26
2.2nF
C33 4.7uF/1206
PN1
R29
IR0
C36
2.2nF
820nH
L2
1800uF/16V
C1 +
1
820nH
L3
1800uF/16V
C18 +
1
820nH
L4
1800uF/16V
C32 +
1
2
2
2
R32
0R0
C4
C5
+
C11
+
C13
+
C17
+
C21
+
C24
+
OUT1
AGND
16
BG
BG
GNDSEN
FB
OSCREF
15
R21
100
8
8
6
7
MSENSE
PGOOD
14
1
1
R9 54.9K
VCC MSENSE
VCC
VID5
VID0
VID4
VID3
2
DRN
DRN
C7 6.8nF
C20 1uF
8
9
10
11
TG
VR EG
(Open-Collector) R15
300
R16 20K
C22 470pF
R20
C25
13
VR EG
7
BG
VID1
7
2
8
VID2
2
TG
VR EG
10
12
PN1
3
TG
BST
7
4.7uF
SC2646
AUX1
C35
1nF
R30
100
BST
V IN
BST
ATX12V
3.3V
R22 R23 R24 R25 R26 R27 1K 1K 1K 1K 1K 1K
DIFFERENTIAL PAIR FOR REMOTE SENSE
V IN
6
V IN
VID0
V_CORE-
V_CORE+
4
6
3
6
VID1
VID2
VID3
VCC
R31 2.9K
R33 1.1K
CO 3
4
4
C27
+
VPN
CO
CO
C31
+
SC1211 SC1211
SC 1211
C34
+
+
5
VPN
VPN
VOUT
1800uF/6.3V
1800uF/6.3V
1800uF/6.3V
1800uF/6.3V
1800uF/6.3V
1800uF/6.3V
1800uF/6.3V
1800uF/6.3V
1800uF/6.3V
1800uF/6.3V
PGND
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© 2005 Semtech Corp.
VID4
VID5
PGOOD (3V3 LOGIC)
C39
10nF
e t e l o s b e O t e l o s b O 5
5
VRM_EN
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HIGH FREQUENCY
SC2646B 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.
e t e l o s b e O t e l o s b O
Parameter
Symbol
Maximum
Units
VCC
20
V
OS1, OS2, OS3, OS4, OUTSEN
5
V
Ambient Temperature Range
TA
0 to 85
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
Supply Voltage
Combi-Sense/Direct Output Voltage
C C C C
Electrical Characteristics
o
Unless specified: VCC = 12V, FOSC = 600kHz, 4 phase operation, VOUT = 1.28V, TA = 27 C. See Typical Application Circuit. Specifications subject to change without notice.
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
7
12
14
V
Chip_Supply
IC Supply Voltage
VCC
e t e l o s b e O t e l o s b O
IC Supply Current
ICC
UVLO Ramp Up
UVLO Hysteresis
700
5.4
8.0
mA
6.3
7.0
V
890
mV
1.5
V
Reference Section Bandgap Output
VBGOUT
CBGOUT = 4.7nF
Source Current
55
Supply Rejection
Temperature Stability (1)
95
μA
VCC = 10.0V ~ 14.0V
0.5
mV/V
0oC < TA < 85oC
0.5
%
VOUT
Internal offset is -20mV
-0.5
Oscillator Frequency
FOSC
ROSC = 320K
540
Oscillator Frequency Range
FOSC
Voltage Accuracy
70
+0.5
%
660
kHz
3000
kHz
Oscillator Section
Temperature Stability (1)
600
500
0oC < TA < 85oC
+/ - 5
%
25
nA
80
dB
Voltage Error Amplifier Input Bias Current (1) Open Loop Gain (1) © 2005 Semtech Corp.
1V < VERROUT < 3.4V 3
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SC2646B POWER MANAGEMENT Electrical Characteristics (Cont.) o
Unless specified: VCC = 12V, FOSC = 600kHz, 4 phase operation, VOUT = 1.28V, TA = 27 C. See Typical Application Circuit. Specifications subject to change without
e t e l o s b e O t e l o s b O
Parameter
Unity Gain Bandwidth (1)
Symbol
Test Conditions
GBW
CERROUT = 10pF
Source Current Sink Current
Transconductance Gain
Min
Typ
Max
5
Units MHz
VBG > 1.8V, VFB = 0V, VERROUT = 0.8V
60
80
90
uA
VBG > 1V, VFB = 2V, VERROUT = 2V
-90
-80
-60
uA
0.62
0.82
1.03
mA/V
GM
Current Sense Amplifiers Input Offset Voltage
VIO
+/-3
mV
Input Bias Current
IM
50
nA
Gca
12.45
V/V
80
dB
Gain CMRR (1)
0 to 3V
Input Common Mode Range
-0.3
Gain Match
5
Bandwidth (1)
6
3
V
6
%
MHz
Droop Amplifier Gain VIDs Logic High
ADRP
VMSENSE-VOUTSEN = 20mV
11.1
11.7
12.3
V/V
e t e l o s b e O t e l o s b O [VID0:5]
0.8
V
[VID0:5]
0.4
V
Internal Pull-up Impedance (1)
[VID0:4]
26
Kohm
Internal Pull-up Voltage (1)
[VID0:4]
1.4
V
Logi c Low
3-Phase Operation
Output 4 pull up Threshold
3.88
4.0
4.5
V
Pow er Good
Threshold Rising
VID - Power Good Threshold
100
mV
Threshold Falling
VID - Power Good Threshold
250
mV
Power Good Delay (1)
From Cross Rising Threshold
Output High Leakage
Pwrgood = VCC
60
Sink Current = 1mA
0.48
0.5
V
3.45
3.63
3.81
V
180
210
280
mV
Output Voltage Low Level
4.0
5
6.5
mS nA
Current Limit Section
Max. Error Amp Voltage for Current Limit
VOC
Shutdown Voltage
V SD
VID - Shut Down Threshold
Note: (1). Guaranteed by design, not tested in production. (2). This device is ESD sensitive. Use of standard ESD handling precautions is required. © 2005 Semtech Corp.
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SC2646B POWER MANAGEMENT Pin Configurations
Ordering Information
Top View
Part Number
Package
Temp. Range (T J)
SC2646BTSTRT (1) (2)
TSSOP-24
0 to 125 OC
e t e l o s b e O t e l o s b O 1 2 3 4 5 6 7 8 9 10 11 12
OS3 OS2 OS1 BGOUT ERROUT GSENSE FB MSENSE VCC VID4 VID3 VID2
24 23 22 21 20 19 18 17 16 15 14 13
OS4 OUTSEN OUT4 OUT3 OUT2 OUT1 AGND OSCREF PGOOD VID5 VID0 VID1
SC2646BEVB
Embedded Evaluation Board
Note: (1) Only available in tape and reel packaging. A reel contains 2500 devices for the TSSOP-24 package. (2) Lead free package.Device is fully WEEE and RoHS compliant.
(24-Pin TSSOP)
Pin Descriptions Pin# 1 2 3
Pin Name
Pin Function
OS3
Current sense input
OS2
Current sense input. Connect to OUTSEN for 2 phase operation.
OS1
Current sense input
4
BGOUT
Bandgap reference voltage. Connect soft start cap to AGND.
5
ERROUT
Error-amplifier output. Connect compensation network to AGND.
GSENSE
Remote sense for GND.
6 7 8 9 10 15 16 17 18
e t e l o s b e O t e l o s b O FB
MSENSE VC C
VID[4:0] VID5
Feedback pin. Route FB and Gsense as differential pair to CPU sense point.
Voltage regulator module output current sense.
Power supply for chip.
VID MSB to LSB.
12.5mV bit.
PGOOD
Power good. Open collector output.
OSCREF
Oscillator frequency setting. Connect a resistor to AGND.
AGND
Clean ground for analog signals.
OUT1
PWM output1.
OUT2
PWM output2.
21
OUT3
PWM output3.
22
OUT4
PWM output4. Connect to VCC for 3 phase operation.
23
OUTSEN
24
OS4
19 20
© 2005 Semtech Corp.
Direct output sense. Current sense input. Connect to OUTSEN for 2 or 3 phase operation. 5
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SC2646B POWER MANAGEMENT Block Diagram C/A1
e t e l o s b e O t e l o s b O OS1
3
+
+
OUT
OUT
-
C/A2
OS2
R
-
Q
19
OUT1
20
OUT2
21
OUT3
22
OUT4
S
+
2
+
OUT
DRV2
PWM2
-
OUT
C/A3
OS3
DRV1
PWM1
R
-
Q
S
+
1
+
OUT
-
OUT
C/A4
OS4 24
DRV3
PWM3
R
-
Q
S
+
+
OUT
OUTSEN
DRV4
PWM4 OUT
-
R
-
Q
S
OUTSEN 23
OSCILLATOR
ERROUT
CLOCK DIVIDER
Ramp
ROSC
OSCREF 17
OSC
CLK
SEL3
P1 P2 P3 P4
+
OUT
VID0
14
VID1
13
VID2
12
Shut Down
DAC VID0 VID1 VID2 VID3 VID4 VID5
3 PHASE SELECT
11111 INHIBIT
-
4.2V
I_DAC
e t e l o s b e O t e l o s b O VID3
11
VID4
10
VID5
15
PWR_GOOD +
OUTSEN
OUT
0.8*VBG
DROOP
16
PWRGD
5
ERROUT
9
VCC
18
AGND
DELAY
-
-
OUT
MSENSE
FB
8
+
-
7
R
ERROUT
E/A OUT
+
OCP & SHUTDOWM
BGOUT
-
BGOUT
4
VBG
OUT
BUFFER
+
VCC
VCC
VREF
GSENSE
UVLO & LATCH
+
BGOUT
-
6
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SC2646B POWER MANAGEMENT Applications Information- Output Voltage VRD10 Output Voltage Unless specified: 0 = GND; 1 = High. TA = 25°C, VCC = 12V
e t e l o s b e O t e l o s b O
VID5 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
VID4 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
VID3 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
VID2 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
VID1 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
VID0 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
e t e l o s b e O t e l o s b O
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SC2646B POWER MANAGEMENT Outline Drawing - TSSOP-24
e t e l o s b e O t e l o s b O DIMENSIONS MILLIMETERS INCHES DIM MIN NOM MAX MIN NOM MAX
A
D
e
A A1 A2 b c D E1 E e L L1 N 01 aaa bbb ccc
N
2X E/2
E1
E
PIN 1 INDICATOR
ccc C 2X N/2 TIPS
1 2 3
e/2
B
1.20 0.15 0.05 1.05 0.80 0.19 0.30 0.20 0.09 7.70 7.80 7.90 4.30 4.40 4.50 6.40 BSC 0.65 BSC 0.45 0.60 0.75 (1.0) 24 0° 8° 0.10 0.10 0.20
D
aaa C
SEATING PLANE
.047 .006 .002 .042 .031 .012 .007 .007 .003 .303 .307 .311 .169 .173 .177 .252 BSC .026 BSC .018 .024 .030 (.039) 24 0° 8° .004 .004 .008
A2 A
C
H
A1 bxN bbb
c
GAGE PLANE
C A-B D
e t e l o s b e O t e l o s b O 0.25
L
(L1)
SIDE VIEW
SEE DETAIL
A
DETAIL
01
A
NOTES: 1. 2. 3. 4.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H-
DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. REFERENCE JEDEC STD MO-153, VARIATION AD.
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SC2646B POWER MANAGEMENT Land Pattern - TSSOP-24
e t e l o s b e O t e l o s b O X
DIM
(C)
G
C G P X Y Z
Z
Y
DIMENSIONS INCHES MILLIMETERS (.222) .161 .026 .016 .061 .283
(5.65) 4.10 0.65 0.40 1.55 7.20
P
NOTES: 1.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET.
e t e l o s b e O t e l o s b O
Contact Information
Semtech Corporation Power Management Products Division 200 Flynn Rd., Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804
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