SEMTECH SC1214TSTR

SC1214
High Speed, Combi-SenseTM
Two-Phase, Synchronous MOSFET Driver
POWER MANAGEMENT
Description
Features
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The SC1214 is a high speed, Combi-SenseTM, two-phase
driver designed to drive high-side and low-side MOSFETs
in two synchronous Buck converters. The driver combined with Combi-Sense PWM controllers, such as
Semtech SC2643VX or SC2643, provides a cost effective two-phase voltage regulator for advanced microprocessors
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The Combi-SenseTM is a technique to sense the inductor
current for peak current mode control of voltage regulator without using sensing resistor. It provides the following advantages:
- No costly precision sensing resistor
- Lossless current sensing
- High level noise free signal
- Fast response
- Suitable for wide range of duty cycle
The detailed explanation of the technique can be found
in the Applications Information section.
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High efficiency
+12V gate drive voltage
High peak drive current
Adaptive non-overlapping gate drives provide
shoot-through protection
Support Combi-SenseTM and VID-on-fly operations
Fast rise and fall times (15ns typical with 3000pf
load)
Ultra-low (<30ns) propagation delay (BG going low)
Floating top gate drive
Crowbar function for over voltage protection
High frequency (to 1.5 MHz) operation allows use
of small inductors and low cost ceramic capacitors
Under-voltage-lockout
Low quiescent current
Applications
A 30ns max propagation delay from input transition to
the gate of the power FET’s guarantees operation at high
switching frequencies. Internal overlap protection circuit
prevents shoot-through from Vin to PGND in the main
and synchronous MOSFETs. The adaptive overlap protection circuit ensures the bottom FET does not turn on
until the top FET source has reached 1V, to prevent crossconduction.
u Intel Pentium® processor power supplies
u AMD AthlonTM and AMD-K8TM processor power
supplies
u High current low voltage DC-DC converters
High current drive capability allows fast switching, thus
reducing switching losses at high (up to 1.5MHz) frequencies without causing thermal stress on the driver.
Under-voltage-lockout and over-temperature shutdown
features are included for proper and safe operation.
Timed latches and improved robustness are built into
the housekeeping functions such as the Under Voltage
Lockout and adaptive Shoot-through protection circuitry
to prevent false triggering and to assure safe operation.
The SC1214 is offered in a TSSOP-20 package.
May 9, 2005
1
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SC1214
POWER MANAGEMENT
Typical Application Circuit
1
ATX12V
1
C5
1800uF/16V
+
L2
L1
640nH
C15
M1
VIN
M5
C18
1uF
R11
R8
VPN1
2
4.7uF/1206
C7
PN2
IR0
R3
C9
2.2nF
R14
1.5K
10
R18
R15
C19
V_COREV_CORE+
M2
M6
C16
C20
0.1uF
VCC
C3
1nF
100
R2
VPN2
R5
C14
1R0
R9
OS2
C17
20
1
2
3
4
5
6
7
8
9
VID3
VID4
VCC
DACSTEP
FB
GNDSEN
ERROUT
BGOUT
OS1
R12
VPN2
C21
4.7uF
VOUT
C1
4.7uF
VIN
C11
D2
10
11
12
14
13
15
16
17
18
19
1uF D1N4148
R10
U2
VID2
VID1
VID0
PGOOD
VID5
OSCREF
AGND
OUT1
OUT2
OUTSEN
R13
SC2642
6
ATX12V
C4
2
Note (1)
+
1800uF/16V
VOUT
VRM_EN
R17
OFFSET-
(Open Collector/Drain Input, No Pull-up)
VCC
R16
OFFSET+
ATX12V
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
1nF
C13
VPN1
100
U1
1uF
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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 2005 Semtech Corp.
BST1
VR EG1
1
DRN1
PGN D
20
BG1
19
C O1
4
VIN 1
17
NC
3
18
VIN 2
7
C O2
5
VPN 1
16
VPN 2
NC
15
8
VR EG2
BST2
13
14
10
PGN D
9
BG2
TG2
12
DRN2
11
SC1214
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
U nits
VI N
16
V
VBST-DRN, VTG-DRN
11
V
BST to PGND
VBST-PGND
40
V
BST to PGND Pulse
VBST-PULSE
45
V
D RN to PGND
VDRN-PGND
-2 to 30
V
D RN to PGND Pulse
VDRN-PULSE
-5 to 35
V
VI N Supply Voltage
BST, TG to D RN
C onditions
tPULSE < 100ns
tPULSE < 200ns
BG to PGND
VBG-PGND
11
V
VREG to PGND
VREG-PGND
11
V
V PN
16
V
20
V
-0.3 to 8.5
V
1.76
W
17
°C /W
TJ
0 to +150
°C
Storage Temperature Range
TSTG
-65 to +150
°C
Lead Temperature (Solderi ng) 10 Sec.
TLEAD
300
°C
VPN to PGND
VPN to PGND Pulse
tPULSE < 100ns
VPN-PULSE
PWM Input
CO
C onti nuous Power D i ssi pati on
PD
TA = 25°C , TJ =125°C
Thermal Resi stance Juncti on to C ase
Operati ng Juncti on Temperature Range
NOTE:
(1) This device is ESD sensitive. Use of standard ESD handling precautions is required.
Electrical Characteristics
Unless specified: TA = 25°C; VIN = 12V; VREG = 8.5V
Parameter
Symbol
C onditions
Min
Typ
Max
U nits
9
12
15
V
Pow er Supply
Supply Voltage
Qui escent C urrent, Operati ng
VI N
Iq_op
3.0
mA
Start Threshold of VREG Voltage
VREG_START
4
Hysteresi s
VhysUVLO
160
mV
U nder Voltage Lockout
4.3
V
Internal LD O
LD O Output
VREG
VI N = 9V to 15V
8.5
V
D rop Out Voltage
VDROP
VI N = 5V to 8.8V
0.3
V
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SC1214
POWER MANAGEMENT
Electrical Characteristics (Cont.)
Unless specified: TA = 25°C; VIN = 12V; VREG = 8.5V
Parameter
Symbol
C onditions
Min
Typ
Max
U nits
C O1, C O2
Logi c Hi gh Input Voltage
VCO_H
Logi c Low Input Voltage
VCO_L
2.0
V
0.8
V
Thermal Shutdow n
Over Temperature Tri p Poi nt
TOTP
155
°C
Hysteresi s
THYST
10
°C
H igh Side D river (TG1, TG2)
Output Impedance
RSRC_TG
RSINK_TG
VBST - VDRN = 8.5V
1.5
3.0
1.0
2.0
Ohm
Ri se Ti me
tR_TG
C L = 3.3nF, VBST - VDRN = 8.5V
15
ns
Fall Ti me
tF_TG
C L = 3.3nF, VBST - VDRN = 8.5V
10
ns
Propagati on D elay, TG Goi ng Hi gh
tPDH_TG
VBST - VDRN = 8.5V
37
ns
Propagati on D elay, TG Goi ng Low
tPDL_TG
VBST - VDRN = 8.5V
30
ns
Low -Side D river (B G1, B G2)
Output Impedance
RSRC_BG
RSINK_BG
VREG = 8.5V
1.5
3.0
1.5
3.0
Ohm
Ri se Ti me
tR_BG
C L = 3.3nF, VREG = 8.5V
10
ns
Fall Ti me
tF_BG
C L = 3.3nF, VREG = 8.5V
10
ns
Propagati on D elay, BG Goi ng Hi gh
tPDH_BG
VREG = 8.5V
20
ns
Propagati on D elay, BG Goi ng Low
tPDL_BG
VREG = 8.5V
27
ns
BG1, BG2 Mi ni mum Off-ti me(1)
tOFF_BG
75
ns
VREG rampi ng up
tPDH_UVLO
2
µs
VREG rampi ng down
tPDL_UVLO
2
µs
U nder-Voltage-Lockout Time D elay
NOTE:
(1) Guaranteed by design.
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SC1214
POWER MANAGEMENT
Timing Diagrams
CO
DRN
1.0V
TG
t PDH_TG
BG
t PDL_TG t F_TG
tR_TG
1.4V
t PDL_BG
tF_BG
tPDH_BG
Rising Edge Transition
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tR_BG
Falling Edge Transition
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SC1214
POWER MANAGEMENT
Ordering Information
Pin Configurations
Device
Top View
SC1214TSTR
SC1214TSTRT(1)(2)
(1)
DRN1
TG1
BST1
CO1
NC
VPN2
VIN2
VREG2
BG2
PGND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
PGND
BG1
VREG1
VIN1
VPN1
NC
CO2
BST2
TG2
DRN2
P ackag e
Temp. Range( Tj)
TSSOP-20
TSSOP-20
0 - 125°C
0 - 125°C
Note:
(1) Only available in tape and reel packaging. A reel
contains 2500 devices.
(2) Lead free product. This product is fully WEEE and RoHS
compliant.
(20-Pin TSSOP)
Pin Descriptions
Pin#
Pin Name
2,12
TG1, TG2
1,11
DRN1, DRN2
The power phase node (or switching node) of the synchronous buck converter. This pin can be
subjected to a negative spike up to -VREG relative to PGND without affecting operation.
3, 13
BST1, BST2
Bootstrap pin. A capacitor is connected between BST and DRN pins to develop the floating
bootstrap voltage for the high-side MOSFET. The capacitor value is typically 1µF (ceramic).
18,8
VREG1,VREG2
4,14
CO1, CO2
16,6
VPN1, VPN2
10, 20
PGND
19,9
BG1, BG2
Output gate drive for the synchronous (bottom) MOSFET.
17,7
VIN1,VIN2
Supply power for low gate drive, LDO and the internal Combi-Sense
input power rail of the converter.
 2005 Semtech Corp.
Pin Function
Output gate drive for the switching (top) MOSFET.
LDO output. Decouple with 1µF to 4.7µF (ceramic) with lead length no more than 0.2" (5mm).
Logic level PWM input signal to the SC1214 supplied by external controller. An internal
50kohm resistor is connected from this pin to PGND.
Virtual Phase Node. Connect an RC between this pin and the output sense point to Enable
Combi-Sense TM operation. See the Typical Application Circuit.
Ground. Keep these pins close to the synchronous MOSFETs source.
6
TM
circuitry. Connect to
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SC1214
POWER MANAGEMENT
Block Diagram
VIN1,2
LDO
UVLO
LOGIC
VREG1,2
VPN1,2
BST1,2
CO1,2
CONTROL
&
OVERLAP
PROT ECTION
CIRCUIT
TG1,2
DRN1,2
PGND
 2005 Semtech Corp.
BG1,2
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SC1214
POWER MANAGEMENT
Outline Drawing - TSSOP-20
A
DIM
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
aaa C
SEATING
PLANE
DIMENSIONS
INCHES
MILLIMETERS
MIN NOM MAX MIN NOM MAX
.002
.031
.007
.003
.251
.169
.047
.006
.042
.012
.007
.255 .259
.173 .177
.252 BSC
.026 BSC
.018 .024 .030
(.039)
20
0°
8°
.004
.004
.008
0.05
0.80
0.19
0.09
6.40
4.30
1.20
0.15
1.05
0.30
0.20
6.50 6.60
4.40 4.50
6.40 BSC
0.65 BSC
0.45 0.60 0.75
(1.0)
20
0°
8°
0.10
0.10
0.20
D
A2 A
C
H
A1
bxN
bbb
C A-B D
c
GAGE
PLANE
0.25
L
(L1)
SEE DETAIL
SIDE VIEW
DETAIL
A
01
A
NOTES:
1.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2.
DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H-
3.
DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
4.
REFERENCE JEDEC STD MO-153, VARIATION AC.
Land Pattern - TSSOP-20
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.
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
 2005 Semtech Corp.
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