Richtek RT8202LGQW, RT8202LZQW, RT8202MGQW, RT8202MZQW Schematic [ru]
Single Synchronous Buck Controller
RT8202L/M
General Description
The RT8202L/M 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 CPU core, I/O, and 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 RT8202L/M 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 RT8202L is available in a
WQFN-16L 4x4 package and the RT8202M is available in
a WQFN-16L 3x3 package.
Ordering Information
RT8202L/M
Package Type
QW : WQFN-16L 4x4 (W-Type)
QW : WQFN-16L 3x3 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Z : ECO (Ecological Element with
Halogen Free and Pb free)
L : WQFN-16L 4x4
M : WQFN-16L 3x3
Note :
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Features
zz
Ultra-High Efficiency
z
zz
zz
z Resistor Programmable Current Limit by Low Side
zz
R
zz
z 4700ppm/
zz
zz
z Quick Load Step Response within 100ns
zz
zz
z 1% V
zz
zz
z Adjustable 0.75V to 3.3V Output Voltage Range
zz
zz
z 3V to 26V Battery Input Voltage Range
zz
zz
z Resistor Programmable Frequency
zz
zz
z Integrated Bootstrap Switch
zz
zz
z Over Voltage Protection
zz
zz
z Under Voltage Protection
zz
zz
z Voltage Ramp Soft-Start
zz
zz
z Built In Soft Discharge Output
zz
zz
z Power Good Indicator
zz
zz
z RoHS Compliant and 100% Halogen Free
zz
Sense (Lossless Limit)
DS(ON)
°°
°C R
°°
Accuracy over Line and Load
FB
Current Sensing
DS(ON)
Applications
z Notebook Computers
z CPU Core Supply
z Chipset/RAM Supply as Low as 0.75V
Pin Configurations
(TOP VIEW)
EN/DEM
GND
NC
1316 1415
17
PGND
BOOT
12
11
10
9
LGATE
UGATE
PHASE
OC
VDDP
VOUT
VDD
FB
PGOOD
TON
1
2
GND
3
4
5678
NC
WQFN-16L 4x4 (RT8202L)/
WQFN-16L 3x3 (RT8202M)
DS8202L/M-04 April 2011 www.richtek.com
1
RT8202L/M
Marking Information
RT8202LGQW RT8202MGQW
EK= : Product Code
EK=YM
DNN
YMDNN : Date Code
JJ=YM
DNN
JJ= : Product Code
YMDNN : Date Code
RT8202LZQW
EK : Product Code
EK YM
YMDNN : Date Code
DNN
Typical Application Circuit
1
6
T
V
P
D
D
V
5
D
O
G
O
P
C
C
D
M
E
/
M
1
C
1
R
6
,
1
E
7
(
x
p
9
V
2
R
2
V
2
C
4
P
1
5
E
o
s
e
d
P
a
d
)
G
7
PGND
RT8202MZQW
JJ : Product Code
JJ YM
YMDNN : Date Code
DNN
V
N
I
3
V
6
2
o
t
V
R
T
O
N
C
R
2
T
8
L
M
0
2
/
B
O
O
N
D
D
P
D
D
D
O
O
G
N
D
E
/
M
D
N
O
U
G
A
T
P
H
A
S
L
G
A
T
O
F
V
O
U
R
3
1
3
T
C
R
4
1
2
E
1
1
E
8
E
R
L
I
I
M
1
0
C
3
B
1
T
3
4
V
O
T
U
Q
1
Q
2
L
1
R
5
*
*
C
5
R
6
R
7
*
C
6
C
C
8
7
*
O
p
t
*
o
i
n
a
l
DS8202L/M-04 April 2011www.richtek.com
2
Function Block Diagram
TRIG
+
+
GM
-
-
SS Ramp
On-time
Compute
1-SHOT
+
-
+
-
VOUT
TON
FB
VDD
GND
SS (Internal)
115% V
70% V
REF
REF
OV
UV
90% V
+
Latch
S1 Q
Latch
S1 Q
REF
Thermal
Shutdown
Comp
+
R
QS
Min. T
OFF
QTRIG
1-SHOT
Emulation
PWM
Diode
RT8202L/M
DRV
DRV
20µA
+
-
BOOT
UGATE
PHASE
VDDP
LGATE
PGND
OC
EN/DEM
PGOOD
DS8202L/M-04 April 2011 www.richtek.com
3
RT8202L/M
Functional Pin Description
Pin No. Pin Name Pin Function
1 VOUT
2 VDD
3 FB
4 PGOOD
5, 14 NC No Internal Connection.
6,
17 (Exposed Pad)
7 PGND Power Ground.
8 LGATE
9 VDDP
10 OC
11 PHASE
12 UGATE
13 BOOT
15 EN/DEM
16 TON
GND
Output Voltage Sense Pin. Connect this pin to the output of PWM converter.
VOUT is also for the output soft discharge when shutdown.
Analog Supply Voltage Input for Internal Analog Integrated Circuit. Bypass this
pin to GND with a 1μF ceramic capacitor.
Feedback Input of PWM Controller. Connect FB to a resistor voltage divider from
VOUT to GND to adjust the output voltage from 0.75V to 3.3V.
Power Good Signal Open-Drain Output of PWM Controller. This pin will be
pulled high when the output voltage is within the target range.
Analog Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
Low Side N-MOSFET Gate-Drive Output for PWM. This pin swings between
PGND to VDDP.
Gate Driver Supply for External MOSFETs. Bypass this pin to PGND with a 1μF
ceramic capacitor.
PWM Current Limit Setting and Sense. Connect a resistor between OC to
PHASE for current limit setting.
Inductor Connection. This pin is not only the zero-current-sense input for the
PWM converter, but also the UGATE high side gate driver return.
High Side N-MOSFET Floating Gate-Driver Output for PWM controller. This pin
swings between PHASE and BOOT.
Boost Capacitor connection for PWM Controller. Connect an external ceramic
capacitor from this pin to PHASE.
PWM Enable and Operation Mode Selection Input. Connect this pin to VDD for
diode-emulation mode, connect this pin to GND for shutdown mode and floating
the pin for CCM mode.
On Time/Frequency Adjustment Pin. Connect this pin to V
TON is an input of the PWM controller.
through a resistor.
IN
DS8202L/M-04 April 2011www.richtek.com
4
RT8202L/M
Absolute Maximum Ratings (Note 1)
z Input Voltage, TON to GND ------------------------------------------------------------------------------------------------ –0.3V to 32V
z BOOT to PHASE ------------------------------------------------------------------------------------------------------------ –0.3V to 6V
z UGATE to PHASE
DC------------------------------------------------------------------------------------------------------------------------------- –0.3V to 6V
< 20ns ------------------------------------------------------------------------------------------------------------------------- −5V to 7.5V
z LGATEx to GND
DC------------------------------------------------------------------------------------------------------------------------------- –0.3V to 6V
< 20ns ------------------------------------------------------------------------------------------------------------------------- −2.5V to 7.5V
z PHASE to GND
DC------------------------------------------------------------------------------------------------------------------------------- –0.3V to 32V
< 20ns ------------------------------------------------------------------------------------------------------------------------- −8V to 38V
z PGND to GND ---------------------------------------------------------------------------------------------------------------- –0.3V to 0.3V
z VDD, VDDP, VOUT, EN/DEM, FB, PGOOD to GND ---------------------------------------------------------------- –0.3V to 6V
z OC to GND -------------------------------------------------------------------------------------------------------------------- –0.3V to 28V
z Power Dissipation, P
WQFN-16L 3x3 -------------------------------------------------------------------------------------------------------------- 1.471W
WQFN-16L 4x4 -------------------------------------------------------------------------------------------------------------- 1.852W
z Package Thermal Resistance (Note 2)
WQFN-16L 3x3, θJA--------------------------------------------------------------------------------------------------------- 68°C/W
WQFN-16L 3x3, θJC-------------------------------------------------------------------------------------------------------- 7.5°C/W
WQFN-16L 4x4, θJA--------------------------------------------------------------------------------------------------------- 54°C/W
WQFN-16L 4x4, θJC-------------------------------------------------------------------------------------------------------- 7°C/W
z Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------------- 260°C
z Junction Temperature ------------------------------------------------------------------------------------------------------- 150°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 Supply Voltage, V
z Junction Temperature Range--------------------------------------------------------------------------------------------- −40°C to 125°C
z Ambient Temperature Range --------------------------------------------------------------------------------------------- −40°C to 85°C
DS8202L/M-04 April 2011 www.richtek.com
------------------------------------------------------------------------------------------------------------ 3V to 26V
IN
, V
DD
------------------------------------------------------------------------------------------------ 4.5V to 5.5V
DDP
5
RT8202L/M
Electrical Characteristics
(VDD = V
Quiescent Current IQ
TON Operating Current -- 15 --
Shutdown Current I
FB Referenc e Volta ge VFB V
FB Input Bias Current VFB = 0.75V −1 0.1 1 μA
Output Voltage Range V
On-Time tON V
Minimum Off-Time t
VOUT Shutdown Discharge
Resistance
Current Sensing
Current Limit Source
Current
Current Limiter Temperature
Coefficient
Current Comparator Offset
Voltage
Zero Crossing Threshold
Voltage
Fault Prote cti on
= 5V, VIN = 15V, V
DDP
EN/DEM
= VDD, R
= 1MΩ, T
TON
= 25°C, unless otherwise specified)
A
Parameter Symbol Test Conditions Min Typ Max Unit
SHDN
+ I
I
VDD
above the regulation point
I
+ I
VDD
I
-- 1 5
TON
, VFB = 0.8V, forced
VDDP
-- 1 10
VDDP
-- -- 1250 μA
EN/DEM = 0V −10 −1 -- μA
= 4.5V to 5.5V 0.742 0.75 0.758 V
DD
0.75 -- 3.3 V
OUT
= 15V, V
IN
250 400 550 ns
OFF
EN/DEM = GND, V
= 1.25V 267 334 401 ns
OUT
= 0.5V -- 20 -- Ω
OUT
LGATE = High 18 20 22 μA
On the basis of 25°C -- 4700 -- ppm/°C
TC
ICS
GND to OC −10 -- 10 mV
PHASE to GND, EN/DEM = 5V −10 -- 5 mV
μA
Current Limit Sense Voltage GND − PHASE, R
Output Under Voltage
Threshold
Over Voltage Protection
Threshold
Over Voltage Fault Delay
Under Voltage Lockout
Threshold
Under Voltage Lockout
Hysteresis
Soft-Start Ramp Time tSS
UVP detect, FB falling edge 60 70 80 %
V
UVP
V
OVP detect, FB rising edge 110 115 120 %
OVP
FB forced above
threshol d
V
UVLO
ΔV
UVLO
Falling edge, PWM disabled below
this level
-- 150 -- mV
From E N hi gh to in ternal VREF
reaches 0.71V (0Æ95%)
= 10kΩ 170 200 230 mV
ILIM
over voltage
-- 20 -- μs
3.7 3 .9 4.1 V
1.5 -- ms
Under Voltage Blank Time From EN signal going high -- 4.5 -- ms
Thermal Shutdown TSD -- 155 °C
Thermal Shutdown
Hysteresis
ΔT
-- 10 -- °C
SD
Driver On-Resistance
UGATE Driver Source R
UGATE Driver Sink R
UGATEs r
UGATEs k
UGATE, High State, BOOT to PHASE
forced to 5V
UGATE, Low State, BOOT to PHASE
forced to 5V
-- 2 -- Ω
-- 1.5 -- Ω
To be continued
DS8202L/M-04 April 2011www.richtek.com
6
Loading...