Preliminary
RT9602
Dual Channel Synchronous-Rectified Buck MOSFET Driver
General Description
The RT9602 is a, twin power channel MOSFET driver
specifically designed to drive four power N-Channel
MOSFETs in a synchronous-rectified buck converter
topology. These drivers combined with a
RT9237/RT9241 series of Multi-Phase Buck PWM
controller provide a complete core voltage regulator
solution for advanced microprocessors.
The RT9602 can provide flexible gate driving for both
high side and low side drivers. This gives more
flexibility of MOSFET selection.
The output drivers in the RT9602 have the capability
to drive a 3000pF load with a 40ns propagation delay
and 80ns transition time. This device implements
bootstrapping on the upper gates with only a single
external capacitor required for each power channel.
This reduces implementation complexity and allows
the use of higher performance, cost effective, N-
Channel MOSFETs. Adaptive shoot-through
protection is integrated to prevent both MOSFETs
from conducting simultaneously.
The RT9602 can detect high side MOSFET drain-to-
source electrical short at power on and pull the 12V
power by low side MOS and cause power supply to
go into over current shutdown to prevent damage of
CPU.
Features
z
Drives Four N-Channel MOSFETs
z
Adaptive Shoot-Through Protection
z
Internal Bootstrap Devices
z
Small 14-Lead SOIC Package
z
5V to 12V Gate-Drive Voltages for Optimal
Efficiency
z
Tri-State Input for Bridge Shutdown
z
Supply Under-Voltage Protection
z
Power ON Over-Voltage Protection
Applications
Core Voltage Supplies for Intel Pentium 4 and
z
AMD Athlon
High Frequency Low Profile DC-DC Converters
z
High Current Low Voltage DC-DC Converters
z
TM
Microprocessors
Pin Configurations
Part Number Pin Configurations
RT9602CS
(Plastic SOP-14)
PWM1
PWM2
LGATE1
PVCC
PGND
LGATE2
GND
TOP VIEW
1
2
3
4
5
6
7
14
13
12
11
10
9
8
VCC
PHASE1
UGATE1
BOOT 1
BOOT 2
UGATE2
PHASE2
Ordering Information
RT9602
Package type
S : SOP-14
Operating temperature range
C: Commercial standard
DS9602-00 January 2002 www.richtek-ic.com.tw
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RT9602
Pin Description
Preliminary
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Pin Name Pin Function
PWM1 Channel 1 PWM Input
PWM2 Channel 2 PWM Input
GND Ground Pin
LGATE1 Lower Gate Drive of Channel 1
PVCC Upper and Lower Gate Driver Power Rail
PGND Lower Gate Driver Ground Pin
LGATE2 Lower Gate Drive of Channel 2
PHASE2
UGATE2 Upper Gate Drive of Channel 2
BOOT2 Floating Bootstrap Supply Pin of Channel 2
BOOT1 Floating Bootstrap Supply Pin of Channel 1
UGATE1 Upper Gate Drive of Channel 1
PHASE1
VCC Control Logic Power Supply
Connect this pin to phase point of channel 2.
Phase point is the connection point of high side MOSFET source and low side MOSFET drain
Connect this pin to phase point of channel 1.
Phase point is the connection point of high side MOSFET source and low side MOSFET drain
www.richtek-ic.com.tw DS9602-00 January 2002
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Function Block Diagram
Preliminary
RT9602
PWM1
PWM2
Internal
5V
19K
19K
Internal
5V
19K
19K
VCC
Control
Logic
Shoot-through
Protection
Pow e r-o n OVP
Shoot-through
Protection
Shoot-through
Protection
Pow e r-o n OVP
PVCC
PGND
PVCC
BOOT1
UGATE1
PHASE1
PVCC
LGATE1
PGND
BOOT2
UGATE2
PHASE2
PVCC
GND
Shoot-through
Protection
LGATE2
PGND
DS9602-00 January 2002 www.richtek-ic.com.tw
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RT9602
Preliminary
Absolute Maximum Ratings
Supply Voltage (VCC) 15V
z
Supply Voltage (PVCC) VCC + 0.3V
z
BOOT Voltage (V
z
Input Voltage (VPWM) GND–0.3V to 7V
z
UGATE V
z
LGATE GND-0.3V to V
z
Package Thermal Resistance
z
SOP-14, θ
Ambient Temperature 0°C ~ 70°C
z
Junction Temperature 0°C ~ 125°C
z
Storage Temperature Range -40°C ~ 150°C
z
Lead Temperature (Soldering, 10 sec.) 260°C
z
ESD Level
z
JA
BOOT-VPHASE
) 15V
PHASE
160°C /W
-0.3V to V
HBM 2KV
MM 200V
Electrical Characteristics
BOOT
PVCC
+0.3V
+0.3V
Parameter Symbol Test Conditions Min Typ Max Units
VCC Supply Current
Bias Supply Current
Power Supply Current
I
VCC
I
PVCC
= 250KHz, V
PWM
Cboot = 0.1µF, Rphase = 20Ω
f
= 250kHz, V
PWM
Cboot = 0.1µF, Rphase = 20Ω
PVCC
PVCC
= 12V,
= 12V,
-- 3 -- mA
-- 8 -- mA
f
Power-On Reset
VCC Rising Threshold 9.1 9.6 10 V
VCC Falling Threshold 7.5 8.1 8.5 V
PWM Input
Maximum Input Current
V
PWM
= 0 or 5V
-- 200 --
µA
PWM Floating Voltage Vcc=12V -- 1.9 -- V
PWM Rising Threshold -- 3.7 -- V
PWM Falling Threshold -- 1.1 -- V
UGATE Rise Time
LGATE Rise Time
UGATE Fall Time
LGATE Fall Time
UGATE Turn-Off Propagation Delay
LGATE Turn-Off Propagation Delay
V
PVCC
V
PVCC
V
PVCC
V
PVCC
V
VCC
V
VCC
= V
= V
= V
= V
= V
= V
= 12V, 3nF load
VCC
= 12V, 3nF load
VCC
= 12V, 3nF load
VCC
= 12V, 3nF load
VCC
= 12V, 3nF load
PVCC
= 12V, 3nF load
PVCC
-- 30 -- ns
-- 30 -- ns
-- 40 -- ns
-- 30 -- ns
-- 60 -- ns
-- 45 -- ns
Shutdown Window 1.1 -- 3.7 V
To be continued
www.richtek-ic.com.tw DS9602-00 January 2002
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Output
Preliminary
Parameter Symbol Test Conditions Min Typ Max Units
RT9602
Upper Drive Source
Upper Drive Sink
Lower Drive Source
Lower Drive Sink
R
UGATEVVCC
R
UGATEVVCC
R
LGATEVVCC
R
LGATEVVCC
Operation Descriptions
The RT9602 has power on protection function which
held UGATE and LGATE low before V
the rising threshold voltage. After the initialization, the
PWM signal takes the control. The rising PWM signal
first forces the LGATE signal turns low then UGATE
signal is allowed to go high just after a non-
overlapping time to avoid shoot-through current. The
falling of PWM signal first forces UGATE to go low.
When UGATE and PHASE signal reach a
predetermined low level, LGATE signal is allowed to
turn high. The non-overlapping function is also
presented between UGATE and LGATE signal
transient.
up across
CC
= 12V, V
= 12V, V
= 12V, V
= V
PVCC
= 12V
PVCC
= 12V
PVCC
= 12V
PVCC
= 12V
The RT9602 implements a power on over-voltage
protection function. If the PHASE voltage exceeds
1.5V at power on, the LGATE would be turn on to pull
the PHASE low until the PHASE voltage goes below
1.5V. Such function can protect the CPU from
damage by some short condition happened before
power on, which is sometimes encountered in the
M/B manufacturing line.
-- 1.5 --
-- 1.45 2
-- 1.6 --
-- 0.75 1
Ω
Ω
Ω
Ω
The PWM signal is recognized as high if above rising
threshold and as low if below falling threshold. Any
signal level in this window is considered as tri-state,
which causes turn-off of both high side and low-side
MOSFET. When PWM input is floating (not
connected), internal divider will pull the PWM to 1.9V
to give the controller a recognizable level. The
maximum sink/source capability of internal PWM
reference is 60µA.
The PVCC pin provides flexibility of both high side
and low side MOSFET gate drive voltages. If 8V, for
example, is applied to PVCC, then high side
MOSFET gate drive is 8V-1.5V(approximately,
internal diode plus series resistance voltage drop).
The low side gate drive voltage is exactly 8V.
DS9602-00 January 2002 www.richtek-ic.com.tw
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RT9602
Typical Application Circuit
12V
Ω
F
10
µ
1
Preliminary
5
14
VCC
11
BOOT1
1µF
F
µ
1
F
µ
1000
H
µ
1.2
12V
PGOOD
10K
1
PVCC
PWM1
UGATE1
PHASE1
12
13
PHB83N03LT
H
µ
2
RT9602
F
µ
1500
×
2
LGATE1
4
3
6
GND
PWM2
UGATE2
9
PHB95N03LT
PGND
PHASE2
8
F
µ
1
F
µ
1000
10
BOOT2
LGATE2
7
1µF
PHB83N03LT
F
µ
2µH
1500
×
PHB95N03LT
CORE
V
3K
ISP1
3K
14
VSEN
13
GND
12
ISN1
+5V
20
F
µ
1
19
VDD
18
17
PWM1
PGOOD
15
ISP2
3K
3K
16
11
ISN2
PWM2
RT9241
VID4
1
VID4
VID2
VID1
VID0
VID3
2
VID3
+5V
4
3
VID2
VID1
COMP
6
5
VID0
15K
2.4K
66pF
ADJ
FB
8
7
2.4K
SS
DVD
9
10
0.1µF
3K
18K
12V
www.richtek-ic.com.tw DS9602-00 January 2002
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Package Information
Preliminary
RT9602
H
M
B
A
C
F
Dimensions In Millimeters Dimensions In Inches
Symbol
Min Max Min Max
A 8.534 8.738 0.336 0.344
B 3.810 3.988 0.150 0.157
C 1.346 1.753 0.053 0.069
D
I
B
J
D 0.330 0.508 0.013 0.020
F 1.194 1.346 0.047 0.053
H 0.178 0.254 0.007 0.010
I 0.102 0.254 0.004 0.010
J 5.791 6.198 0.228 0.244
M 0.406 1.270 0.016 0.050
14–Lead SOP Plastic Package
DS9602-00 January 2002 www.richtek-ic.com.tw
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RT9602
Preliminary
RICHTEK TECHNOLOGY CORP.
Headquarter
6F, No. 35, Hsintai Road, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5510047 Fax: (8863)5537749
www.richtek-ic.com.tw DS9602-00 January 2002
RICHTEK TECHNOLOGY CORP.
Taipei Office (Marketing)
8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek-ic.com.tw
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