Richtek RT8207GQW Schematic [ru]
RT8207
Complete DDRII/DDRIII Memory Power Supply Controller
General Description
The RT8207 provides a complete power supply for both
DDRII/DDRIII memory systems. It integrates a
synchronous PWM buck controller with a 3A sink/source
tracking linear regulator and a buffered low noise reference.
The PWM controller provides the high efficiency, excellent
transient response, and high DC output accuracy needed
for stepping down high-voltage batteries to generate low
voltage chipset RAM supplies in notebook computers.
The constant-on-time PWM control scheme handles wide
input/output voltage ratios with ease and provides 100ns
“instant-on” response to load transients while maintaining
a relatively constant switching frequency.
The RT8207 achieves high efficiency at a reduced cost
by eliminating the current-sense resistor found in
traditional current-mode PWMs. Efficiency is further
enhanced by its ability to drive very large synchronous
rectifier MOSFETs. The buck conversion allows this device
to directly step down high-voltage batteries for the highest
possible efficiency.
The 3A sink/source LDO maintains fast transient response
only requiring 20μF of ceramic output capacitance. In
addition, the LDO supply input is available externally to
significantly reduce the total power losses. The RT8207
supports all of the sleep state controls placing VTT at
High-Z in S3 and discharging VDDQ, VTT and VTTREF
(soft-off) in S4/S5.
Features
zz
PWM Controller
z
zz
``
` Resistor Progra mmable Current Limit by Low-Side
``
R
``
` Quick Load-Step Response within 100ns
``
``
` 1% V
``
``
` Fixed 1.8V (DDRII), 1.5V (DDRIII) or Adjustable
``
DS(ON)
OUT
Sense
Accuracy Over Line and Load
0.75V to 3.3V Output Range
``
` Battery Input Range 2.5V to 26V
``
``
` Resistor Programmable Frequency
``
``
` Over/Under Voltage Protection
``
``
` 4 Steps Current Limit During Soft-Start
``
``
` Drives Large Synchronous-Re ctifier FETs
``
``
` Power-Good Indicator
``
zz
z 3A LDO (VTT), Buffered Reference (VTTREF)
zz
``
` Capable to Sink and Source Up to 3A
``
``
` LDO Input Available to Optimize Power Losses
``
``
` Requires Only 20
``
``
` Buffered Low Noise 10mA VTTREF Output
``
``
` Accuracy
``
``
` Supports High-Z in S3 and Soft-Off in S4/S5
``
zz
z RoHS Compliant and Halogen Free
zz
±±
±20mV for Both VTTREF and VTT
±±
μμ
μF Ceramic Output Capacitor
μμ
Applications
z DDRII/DDRIII Memory Power Supplies
z Notebook Computers
z SSTL18, SSTL15 and HSTL Bus Termination
The RT8207 has all of the protection features including
thermal shutdown and is available in the WQFN-24L 4x4
Pin Configurations
(TOP VIEW)
package.
UGATE
BOOT
21 20 1924 2223
S3
FB
PHASE
25
S5
LGATE
18
17
16
15
14
13
TON
PGND
NC
CS
VDDP
VDD
PGOOD
VTT
Ordering Information
RT8207
Package Type
QW : WQFN-24L 4x4 (W-Type)
Lead Plating System
Note :
Richtek products are :
` RoHS compliant and compatible with the current require-
G : Green (Halogen Free and Pb Free)
VTTGND
VTTSNS
GND
MODE
VTTREF
DEM
VLDOIN
1
2
3
GND
4
5
6
78910 1211
NC
VDDQ
WQFN-24L 4x4
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
DS8207-07 March 2011 www.richtek.com
1
RT8207
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
Typical Application Circuit
1
2
1
D
P
V
D
V
5
D
P
O
O
G
V
T
T
1
C
F
µ
1
2
R
k
0
0
1
V
T
/
T
R
E
C
F
o
n
V
D
C
D
Q
o
n
D
s
i
c
h
r
a
g
e
M
o
C
C
D
E
/
M
1
R
.
1
5
2
C
F
µ
1
o
l
r
t
o
l
r
t
d
e
M
3
E
p
x
o
,
s
e
d
5
1
4
3
R
.
6
5
k
1
6
1
3
1
0
1
1
4
6
P
a
d
(
2
5
)
1
8
1
R
T
O
N
V
D
D
P
D
D
V
S
C
D
O
O
G
P
S
3
S5
MODE
DEM
D
N
G
PGND
VTTGND
V
I
N
2
5
.
o
2
t
6
V
R
4
6
2
0
k
R
T
8
2
0
7
2
B
U
G
P
H
L
G
L
V
V
V
T
T
V
T
T
2
O
O
T
2
1
T
A
E
2
0
A
S
E
1
9
T
E
A
9
F
B
2
3
D
O
I
N
8
D
Q
D
2
4
T
T
V
2
N
S
S
5
R
E
F
5
0
6
R
B
C
4
0
1
.
µ
F
0
Q
S
C
2
0
2
3
N
0
3
5
C
8
1
0
µ
C
3
3
3
n
F
V
C
9
1
0
µ
F
x
3
V
V
D
D
Q
1
2
.
Q
1
B
C
0
S
9
L
1
1
µ
4
N
0
3
x
F
2
H
5
R
7
R
5
C
8
C
6
R
1
6
k
C
9
0
k
9
0
.
V
C
7
2
0
2
µ
F
1
µ
F
Figure A. Adjustable Voltage Regulator
V
I
N
2
5
V
.
2
V
o
t
6
R
4
6
2
0
k
C
R
T
8
R
2
0
2
1
T
O
N
5
P
D
D
V
V
5
O
D
O
G
P
V
T
T
1
C
F
µ
1
2
R
k
0
0
1
T
T
R
V
/
D
C
F
o
E
V
D
D
Q
C
o
s
i
c
e
h
g
a
r
M
C
C
D
/
M
R
1
5
.
1
2
C
F
µ
1
n
o
l
t
r
o
n
l
t
r
o
e
d
E
M
,
3
E
x
p
s
o
e
1
V
D
D
4
1
D
V
D
3
R
k
.
6
5
1
6
S
C
3
1
O
G
P
1
0
S
3
1
1
S5
4
MODE
6
DEM
a
d
d
P
2
)
5
(
8
1
1
D
N
G
PGND
VTTGND
7
2
B
P
G
U
H
P
L
G
D
O
V
V
L
T
T
V
T
T
V
2
O
O
T
2
1
A
T
E
2
0
A
S
E
1
9
A
T
E
8
D
D
Q
2
3
N
D
O
I
2
4
V
T
T
2
S
N
S
5
R
E
F
9
F
B
5
0
R
6
C
4
1
0
µ
.
F
0
2
B
S
3
Q
C
0
2
3
N
0
3
5
C
7
1
µ
0
x
F
2
C
3
3
n
F
D
V
D
P
N
G
f
D
8
1
0
µ
x
F
2
V
D
V
D
Q
1
8
V
.
5
V
.
1
Q
1
B
S
C
0
9
L
1
µ
H
4
3
N
0
D
o
f
r
D
o
r
D
1
5
R
7
C
5
I
D
R
I
I
I
I
R
/
C
6
2
2
0
µ
F
Figure B. Fixed Voltage Regulator
DS8207-07 March 2011www.richtek.com
2
Function Block Diagram
TRIG
GM
+
On-time
Compute
1-SHOT
+
-
VDDQ
TON
Comp
-
+
RT8207
R
PWM
QS
DRV
BOOT
UGATE
FB
VDD
S5
S3
MODE
115% V
70% V
Discharge
Mode
Select
V
REF
REF
REF
0.75V
+
-
-
+
SS Timer
90% V
PWM
OV
UV
Latch
S1 Q
Latch
S1 Q
REF
Thermal
Shutdown
Min. T
OFF
QTRIG
1-SHOT
DRV
Diode
-
+
+
-
+
-
Emulation
+
-
+
-
-
+
-
GM
+
VDD
10µA
PHASE
VDDP
LGATE
PGND
CS
DEM
PGOOD
VTTREF
VLDOIN
VTT
VTTSNS
GND
110% V
90% V
VTTREF
VTTREF
-
+
-
+
VTTGND
DS8207-07 March 2011 www.richtek.com
3
RT8207
Functional Pin Description
Pin No. Pin Name Pin Function
1 VTTGND Power Ground for the VTT_LDO.
2 VT T SNS
3,
25 (Exposed Pad)
4 MODE
5 VTTREF VTTREF Buffered Reference Output.
6 DE M
7, 17 NC No Internal Connection.
8 VD DQ
9 FB
10 S3 S3 Signal Input.
11 S5 S5 Signal Input
12 TON
13 PGOOD
14 VDD Supply Input for the Analog Supply.
15 VDDP Supply Input for the Low Gate Driver.
16 CS
18 PGND Power Ground for Low-Side MOSFET.
19 LGATE Low-Side Gate Driver Output for VDDQ.
20 PHASE
21 UGATE High-Side Gate Driver Output for VDDQ.
GND
Voltage Sense Input for the VTT_LDO. Connect to the terminal of the VTT_LDO
output capacitor
Analog Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
Output Discharge Mode Setting Pin. Connect to VDDQ for tracking discharge.
Connect to GND for non-tracking discharge. Connect to VDD for no discharge.
Diode-Emulation Mode Enable Pin. Connect to VDD will enable diode-emulation
mode. Connect to GND will always operate in forced CCM mode.
VDDQ Reference Input for VTT and VTTREF. Discharge current sinking terminal
for VDDQ non-tracking discharge. Output voltage feedback input for VDDQ
output if FB pin is connected to VDD or GND
VDDQ Output Setting Pin. Connect to GND for DDRIII (V
supply. The pin should be connect to VDD for DDRII (V
or be connected to a resistive voltage divider from VDDQ to GND to adjust the
output of PWM from 0.75V to 3.3V.
The pin is used to set the UGATE on time through a pull-up resistor connecting to
.
V
IN
Power-Good Open-Drain Output. This pin will be in HIGH state when VDDQ
output voltage is within the target range.
Current Limit Threshold Setting Input. Connect this pin to VDD through the
voltage setting resistor.
External Inductor Connection for VDDQ and it behaves as the current sense
comparator input for Low-Side MOSFET R
DS(ON)
DDQ
sensing.
= 1.5V) power
DDQ
= 1.8V) power supply
22 BOOT Boost Flying Capacitor Connection for VDDQ.
23 VLDOIN Power Supply for the VTT_LDO.
24 VTT Power Output for the VTT_LDO
DS8207-07 March 2011www.richtek.com
4
RT8207
Absolute Maximum Ratings (Note 1)
z Input Voltage, TON to GND ---------------------------------------------------------------------------------------------- –0.3V to 32V
z BOOT to GND -------------------------------------------------------------------------------------------------------------- –0.3V to 38V
z PHASE to GND
DC----------------------------------------------------------------------------------------------------------------------------- −0.3V to 32V
<20ns ------------------------------------------------------------------------------------------------------------------------ −8V to 38V
z PHASE to BOOT ---------------------------------------------------------------------------------------------------------- –6V to 0.3V
z VDD, VDDP, CS, MODE, S3, S5, VTTSNS, VDDQ, DEM to GND -------------------------------------------- –0.3V to 6V
z VTTREF, VTT, VLDOIN, FB, PGOOD to GND ---------------------------------------------------------------------- –0.3V to 6V
z UGATE to PHASE
DC----------------------------------------------------------------------------------------------------------------------------- −0.3V to 6V
<20ns ------------------------------------------------------------------------------------------------------------------------ −5V to 7.5V
z LGATE to GND
DC----------------------------------------------------------------------------------------------------------------------------- −0.3V to 6V
<20ns ------------------------------------------------------------------------------------------------------------------------ −2.5V to 7.5V
z PGND, VTTGND to GND ------------------------------------------------------------------------------------------------- –0.3V to 0.3V
z Power Dissipation, P
WQFN-24L 4x4 ----------------------------------------------------------------------------------------------------------- 1.923W
z Package Thermal Resistance (Note 2)
WQFN-24L 4x4, θJA------------------------------------------------------------------------------------------------------- 52°C/W
WQFN-24L 4x4, θJC------------------------------------------------------------------------------------------------------ 7°C/W
z Junction Temperature ----------------------------------------------------------------------------------------------------- 150°C
z Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------- 260°C
z Storage Temperature Range -------------------------------------------------------------------------------------------- –65°C to 150°C
z ESD Susceptibility (Note 3)
HBM (Human Body Mode) ---------------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ------------------------------------------------------------------------------------------------------ 200V
@ TA = 25°C
D
Recommended Operating Conditions (Note 4)
z Input Voltage, V
z Control Voltage, V
z Junction Temperature Range-------------------------------------------------------------------------------------------- −40°C to 125°C
z Ambient Temperature Range-------------------------------------------------------------------------------------------- −40°C to 85°C
---------------------------------------------------------------------------------------------------------- 2.5V to 26V
IN
, VDD---------------------------------------------------------------------------------------------- 4.5V to 5.5V
DDP
Electrical Characteristics
(V
= V
DD
= 5V, V
DDP
Parameter Symbol Test Conditions Min Typ Max Unit
PWM Controller
Quiescent Supply Current
(VDD + VDDP)
TON Operating Current R
I
I
DS8207-07 March 2011 www.richtek.com
BIAS Current VS5 = VS3 = 5V, VTT = No Load -- 1 -- μA
VLDOIN
Standby Current V
VLDOIN
= 15V, DEM = V
IN
, R
DD
= 1MΩ, T
TON
= 25°C, unless otherwise specified)
A
FB forced above the regulation point,
= 5V, V
V
S5
= 1MΩ -- 15 -- μA
TON
= 5V, VS3= 0, VTT = No Load -- 0.1 10 μA
S5
S3
= 0V
-- 470 1000 μA
To be continued
5
RT8207
Parameter Symbol Test Conditions Min Typ Max Unit
Shutdown current
= VS3 = 0V)
(V
S5
FB Reference Voltage V
Fixed VDDQ Output Voltage
V
TON -- 0.1 5
S3/S5/DEM = 0V −1 0.1 1
I
VDD = 4.5V to 5.5V 0.742 0.75 0.758 V
REF
FB = GND -- 1.5 --
FB = V
+ V
DD
VLDOIN
-- 0.1 10
DDP
μA
-- 0.1 1
-- 1.8 --
DD
V
FB Input Bias Current FB = 0.75V −1 0.1 1 μA
VDDQ Voltage Range 0.75 -- 3.3 V
On-Time, VIN = 15V R
= 1MΩ 267 334 401 ns
TON
Minimum Off-Time 250 400 550 ns
VDDQ Input Resistanc e -- 100 -- kΩ
VDDQ Shutdown Discharge
Resistance
V
= GND -- 15 -- Ω
S5
Curr ent Sensin g
CS Sink Current VCS > 4.5V, After UV Blank Time 9 10 11 μA
Current Comparator Offset GND − PHASE −15 -- 15 mV
Zero Crossing Threshold PHASE − GND, DEM = 5V −10 -- 5 mV
Fault Protection
Current Lim it (Pos itive)
GN D − PHASE, RCS = 5kΩ 35 50 65 mV
GN D − PHASE, R
= 20kΩ 170 200 230 mV
CS
Output UV Threshold 60 70 80 %
OVP Threshold
With respect to error comparator
threshold
10 15 20 %
OV Fault Delay FB forced above OV threshold -- 20 -- μs
VDDP Under voltage Lockout
Threshold
Rising edge, hysteresis = 20mV,
PWM disabled below this level
3.9 4.2 4.5 V
Current Limit Step Time at Soft Start Each step -- 128 -- clks
UV Blank Time From S5 signal going high -- 512 -- clks
Thermal Shutdown Hysteresis = 10°C -- 165 -- °C
Driver On-Resistance
UGATE Gate Driver (pull up) (BOOT − PHASE) forced to 5V -- 2 4 Ω
UGATE Gate Driver (sink) (BOOT − PHASE) forced to 5V -- 1 3 Ω
LGATE Gate Driver (pull up) LGATE, High State (source) -- 2.5 6 Ω
LGATE Gate Driver (pull down) LGATE, Low State (sink) -- 0.6 1.5 Ω
UGATE Gate Driver Source/Sink
Current
UGATE forced to 2.5V,
(BOOT − PHASE ) forced to 5V
-- 1 -- A
LGATE Gate Driver Source Current LGATE Forced to 2.5V -- 1 -- A
LGATE Gate Driver Sink Current LGATE Forced to 2.5V -- 3 -- A
Dead Time
LGATE Rising (PHASE = 1.5V) -- 40 --
UGATE Rising -- 40 --
Internal boost charging switch on
resistance
VDDP to BOOT, 10mA -- -- 80 Ω
To be continued
DS8207-07 March 2011www.richtek.com
6
ns
RT8207
Parameter Symbol Test Conditions Min Typ Max Unit
Logic I/O
Logic Input Low Voltage S3, S5, DEM Low -- -- 0.8 V
Logic Input High Voltage S3, S5, DEM High 2 -- -- V
Logic Input Current S3/S5/DEM = VDD/GND −1 0 1 μA
PGOOD (upper side t hreshold decid e by OV threshold)
Trip Threshold (falling)
Fault Propagation Delay
Output Low Voltage I
Leakage Current High state, forced to 5.0V -- -- 1 μA
VTT LDO TA = 25°C, Unless Otherwise specification
VTT Output Tolerance V
VTT Source Current Limit I
VTT Sink Current Limit I
VTT Leakage Current I
VTTFB Leakage Current I
VTT Discharge Current I
VTTREF Output Voltage V
VDDQ/2, VTTREF Output
Voltage Tolerance
VTTREF Source Current
Limit
VTTTOL
VTTOCLSRC
VTTOCLSNK
VTTLK
VTTSNSLK
DSCHRG
VTTREF
V
VTTREFTOL
I
VTTREFOCL
Measured at FB, with respect to
reference, no load. Hysteresis = 3%
Falling edge, FB forced below
PGOOD trip threshold
= 1mA -- -- 0.4 V
SINK
V
= V
DDQ
⏐I
⏐= 0A
VTT
V
= V
DDQ
⏐I
⏐ = 1A
VTT
= V
V
DDQ
⏐I
⏐= 2A,
VTT
VTT = 0.95
⎛⎞
⎜⎟
⎝⎠
LDOIN
LDOIN
LDOIN
V
DDQ
2
= 1.5V/1.8V,
= 1.5V/1.8V,
= 1.5V/1.8V,
×
,
−13 −10 −7 %
-- 2.5 -- μs
−20 -- +20
−30 -- +30
−40 -- +40
3 -- 6
PGOOD = High
VTT = 0V -- 2 --
VTT = 1.05
V
DDQ
⎛⎞
⎜⎟
⎝⎠
×
2
3 -- 6
PGOOD = High
VTT = VDDQ -- 2 -S5 = 5V, S3 = 0V,
VTT =
I
SINK
V
DDQ
S5 = S3 = 0V
V =
VTTREF
V
LDOIN
⏐I
VTTRE F
V
LDOIN
⏐I
VTTRE F
V
VTTRE F
V
⎛⎞
DDQ
⎜⎟
⎝⎠
2
= 1mA −1 -- 1 μA
= 0V, VTT = 0.5V,
V
⎛⎞
DDQ
⎜⎟
⎝⎠
= V
DDQ
-- 0.9/0.75 -- V
2
= 1.5V,
⏐ < 10mA
= V
DDQ
= 1.8V,
⏐ < 10mA
= 0V 10 40 80 mA
−10 -- 10 μA
10 30 -- mA
−15 -- +15
−18 -- +18
mV
A
A
mV
DS8207-07 March 2011 www.richtek.com
7
Loading...