®
RT9199
Cost-Effective, 2A Peak Sink/Source Bus Termination Regulator
General Description
Features
The RT9199 is a simple, cost-effective and high-speed
linear regulator designed to generate termination voltage
in Double Data Rate (DDR) memory system to comply
with the devices requirements. The regulator is capable
of actively sinking or sourcing up to peak 2A for DDRII or
1.5A for DDRIII while regulating an output voltage to within
20mV. The output termination voltage can be tightly
regulated to track 1/2VDDQ by two external voltage divider
resistors or the desired output voltage can be pro-grammed
by externally forcing the REFEN pin voltage.
The RT9199 also incorporates a high-speed differential
amplifier to provide ultra-fast response in line/load transient.
Other features include extremely low initial offset voltage,
excellent load regulation, current limiting in bi-directions
and on-chip thermal shut-down protection.
The RT9199 are available in both SOP-8 and SOP-8
(Exposed Pad) surface mount packages.
Sink and Source Current :
Peak 2A for DDRII
Peak 1.5A for DDRIII
Integrated Power MOSFETs
Generate Termination Voltage for DDR Memory
Interfaces
High Accuracy Output Voltage at Full-Load
Output Adjustment by Two External Resistors
Low External Component Count
Shutdown for Suspend to RAM (STR) Functionality
with High-Impedance Output
Current Limiting Protection
On-Chip Thermal Protection
RoHS Compliant and Halogen Free
Applications
Ordering Information
RT9199
Package Type
S : SOP-8
SP : SOP-8 (Exposed Pad-Option 2)
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Z : ECO (Ecological Element with
Halogen Free and Pb free)
Ideal for DDRII / DDRIII VTT Applications
Desktop PCs, Notebooks, and Workstations
Graphics Card Memory Termination
Set Top Boxes, Digital TVs, Printers
Embedded Systems
Active Termination Buses
DDR/II Memory Systems
Pin Configurations
(TOP VIEW)
Note :
Richtek products are :
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
8
VCNTL
GND
2
7
VCNTL
REFEN
3
6
VOUT
4
5
VCNTL
VCNTL
8
NC
VIN
SOP-8
VIN
GND
2
REFEN
3
VOUT
7
GND
6
9
4
5
NC
VCNTL
NC
SOP-8 (Exposed Pad)
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
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is a registered trademark of Richtek Technology Corporation.
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RT9199
Marking Information
RT9199xS
RT9199xSP
RT9199xS : Product Number
RT9199
xSYMDNN
RT9199xSP : Product Number
RT9199
xSPYMDNN
x : P or G or Z
YMDNN : Date Code
x : P or G or Z
YMDNN : Date Code
Typical Application Circuit
VCNTL = 5V
VIN = 1.8V/1.5V
RTT
R1
VIN
2N7002
EN
VCNTL
CCNTL
CIN
RT9199
REFEN
VOUT
CSS
R2
GND
COUT RDUMMY
R1 = R2 = 100kΩ, RTT = 50Ω / 33Ω / 25Ω
COUT(MIN) = 10μF (Ceramic) + 1000μF under the worst case testing condition
RDUMMY = 1kΩ as for VOUT discharge when VIN is not presented but VCNTL is presented
CSS = 1μF, CIN = 470μF (Low ESR), CCNTL = 47μF
Test Circuit
VIN = 1.8V/1.5V
VIN
0.9V/0.75V
VCNTL = 5V
VCNTL
RT9199
REFEN
VOUT
VOUT
GND
COUT
V
IL
Figure 1. Output Voltage Tolerance, ΔVLOAD
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is a registered trademark of Richtek Technology Corporation.
DS9199-11 April 2014
RT9199
VCNTL = 5V
A
VIN = 1.8V/1.5V
VIN
VCNTL
RT9199
REFEN
VOUT
0.9V/0.75V
VOUT
0.9V
0V
GND
0.15V
COUT
RL
V
RL and COUT
Time deleay
Figure 2. Current in Shutdown Mode, ISTBY
VCNTL = 5V
VIN = 1.8V/1.5V
VIN
0.9V/0.75V
VCNTL
RT9199
REFEN
VOUT
VOUT
A
GND
COUT
V
IL
Figure 3. Current Limit for High Side, ILIM
Power Supply
with Current Limit
VCNTL = 5V
VIN = 1.8V/1.5V
VIN
0.9V/0.75V
A
VCNTL
IL
RT9199
REFEN
VOUT
VOUT
GND
COUT
V
Figure 4. Current Limit for Low Side, ILIM
VCNTL = 5V
VIN = 1.8V/1.5V
VIN
0.9V/0.75V
VREFEN
VCNTL
RT9199
REFEN
VOUT
GND
0.15V
VOUT
RL
COUT
V
0.9V/0.75V
VOUT
0V
VOUT would be low if V REFEN < 0.15V
VOUT would be high if V REFEN > 0.6V
RL and COUT
Time deleay
Figure 5. REFEN Pin Shutdown Threshold, VIH & VIL
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
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is a registered trademark of Richtek Technology Corporation.
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RT9199
Functional Pin Description
VIN
REFEN
Input voltage which supplies current to the output pin.
Connect this pin to a well-decoupled supply voltage. To
prevent the input rail from dropping during large load
transient, a large, low ESR capacitor is recommended to
use. The capacitor should be placed as close as possible
to the VIN pin.
Reference voltage input and active low shutdown control
pin. Two resistors dividing down the VIN voltage on the
pin to create the regulated output voltage. Pulling the pin
to ground turns off the device by an open-drain, such as
2N7002, signal N-MOSFET.
VOUT
GND (Exposed Pad)
Regulator output. VOUT is regulated to REFEN voltage
that is used to terminate the bus resistors. It is capable
of sinking and sourcing current while regulating the output
rail. To maintain adequate large signal transient response,
typical value of 1000μF Al electrolytic capacitor with 10μF
ceramic capacitors are recommended to reduce the effects
of current transients on VOUT.
Common Ground. The exposed pad must be soldered to
a large PCB and connected to GND for maximum power
dissipation.
VCNTL
VCNTL supplies the internal control circuitry and provides
the drive voltage. The driving capability of output current
is proportioned to the VCNTL. Connect this pin to 5V bias
supply to handle large output current with at least 1μF
capacitor from this pin to GND. An important note is that
VIN should be kept lower or equal to VCNTL.
Function Block Diagram
VCNTL
VIN
Current Limit
Thermal Protection
+
REFEN
VOUT
EA
GND
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is a registered trademark of Richtek Technology Corporation.
DS9199-11 April 2014
RT9199
Absolute Maximum Ratings
(Note 1)
Input Voltage, VIN ---------------------------------------------------------------------------------------------------------Control Voltage, VCNTL --------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
SOP-8 ----------------------------------------------------------------------------------------------------------------------SOP-8 (Exposed Pad) -------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
SOP-8, θJA -----------------------------------------------------------------------------------------------------------------SOP-8, θJC -----------------------------------------------------------------------------------------------------------------SOP-8 (Exposed Pad), θJA ---------------------------------------------------------------------------------------------SOP-8 (Exposed Pad), θJC --------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Model) ---------------------------------------------------------------------------------------------MM (Machine Model) -----------------------------------------------------------------------------------------------------
Recommended Operating Conditions
6V
6V
0.909W
2.33W
110°C/W
60°C/W
42.9°C/W
12.6°C/W
125°C
260°C
–65°C to 150°C
2kV
200V
(Note 4)
Input Voltage, VIN ---------------------------------------------------------------------------------------------------------- 1.4V to 5.5V
Control Voltage, VCNTL --------------------------------------------------------------------------------------------------- 5V ± 5%
Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C
Electrical Characteristics
(VIN = 1.8V/1.5V, VCNTL = 5V, VREFEN = 0.9V/0.75V, COUT = 10μF (Ceramic), TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Input
VCNTL Operation Current
I CNTL
I OUT = 0A
--
1
2.5
mA
Standby Current
I STBY
VREFEN 0.2V (Shutdown),
RLOAD = 180
--
2
90
A
I OUT = 0A
10
--
10
mV
VIN = 1.8V, VREFIN = 0.9V, IOUT = 1.8A
20
--
20
VIN = 1.5V, VREFIN = 0.75V, I OUT = 1.4A
10
--
10
2
--
3.5
VIN = 1.5V, VREFIN = 0.75V
1.5
--
3.5
VCNTL = 5V
125
170
--
C
TSD
VCNTL = 5V
--
35
--
C
V IH
Enable
0.6
--
--
V IL
Shutdown
--
--
0.15
(Note 5)
Output (DDR II)
Output Offset Voltage
Load Regulation
(Note 6) V OS
(Note 7)
VLOAD
mV
Protection
Current limit
I LIMIT
Thermal Shutdown Temperature T SD
Thermal Shutdown Hysteresis
VIN = 1.8V, VREFIN = 0.9V
A
REFEN Shutdown
Shutdown Threshold
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RT9199
Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in
the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may
affect device reliability.
Note 2. θJA is measured in the natural convection at TA = 25°C on a high effective thermal conductivity test board (4 Layers,
2S2P) of JEDEC 51-7 thermal measurement standard. The case point of θJC is on the exposed pad for package.
Note 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. Standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown signal on
REFEN pin (VIL < 0.15V). It is measured with VIN = VCNTL = 5V.
Note 6. VOS offset is the voltage measurement defined as VOUT subtracted from VREFEN.
Note 7. Regulation is measured at constant junction temperature by using a 5ms current pulse. Devices are tested for load
regulation in the load range from 0A to 2A peak.
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RT9199
Typical Operating Characteristics
Output Voltage vs. Temperature
0.920
VCNTL Pin Current vs. Temperature
0.6
VIN = 1.8V, VCNTL = 5V
VIN = 1.8V, VCNTL = 5V
Vcntl Pin Current (mA)
Output Voltage (V)
0.915
0.910
0.905
0.900
0.895
0.890
0.5
0.4
0.3
0.2
0.885
0.1
0.880
-50
-25
0
25
50
75
100
-50
125
-25
0
Source Current Limit (A)
Source Current Limit (A)
3.5
VIN = 1.8V, VCNTL = 5V
3.0
2.5
2.0
1.5
1.0
0.5
0.0
100
125
VIN = 1.8V, VCNTL = 5V
3.0
2.5
2.0
1.5
1.0
0.5
-25
0
25
50
75
100
125
-50
-25
0
Temperature (°C)
25
50
75
100
125
Temperature (°C)
Shutdown Threshold vs. Temperature
VIN Current vs. Temperature
0.60
Shutdown Threshold (V)
VIN = 1.8V, VCNTL = 5V
2.5
VIN Current (mA)
75
0.0
-50
3.0
50
Sink Current Limit vs. Temperature
Source Current Limit vs. Temperature
3.5
25
Temperature (°C)
Temperature (°C)
2.0
1.5
1.0
0.5
RT9199SP, VCNTL = 5V
0.55
0.50
Turn On
0.45
0.40
0.35
Turn Off
0.30
0.25
0.20
0.0
-50
-25
0
25
50
75
100
Temperature (°C)
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
DS9199-11 April 2014
125
-50
-25
0
25
50
75
100
125
Temperature (°C)
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RT9199
Output Short-Circuit Protection
Sink
Output Short-Circuit Protection
VIN = 1.8V, VCNTL = 5V
Sink
10
8
6
4
2
0
6
4
2
Time (1ms/Div)
Output Short-Circuit Protection
Output Short-Circuit Protection
Source
VIN = 1.8V, VCNTL = 5V
VIN = 2.5V, VCNTL = 5V
12
Output Short Circuit (A)
Output Short Circuit (A)
8
Time (1ms/Div)
Source
10
8
6
4
2
10
8
6
4
2
0
0
Time (1ms/Div)
Time (1ms/Div)
0.9VTT @ 1.8A Transient Response
1.25VTT @ 1.8A Transient Response
VIN = 1.8V, VCNTL = 5V, VOUT = 0.9V
50 Swing Frequency : 10kHz
0
-50
Output Voltage
Transient (mV)
Output Voltage
Transient (mV)
10
0
12
2
1
0
-1
-2
0
-50
1
0
-1
-2
Time (25μs/Div)
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VIN = 2.5V, VCNTL = 5V, VOUT = 1.25V
50 Swing Frequency : 10kHz
2
Output Current
(A)
Output Current
(A)
VIN = 2.5V, VCNTL = 5V
12
Output Short Circuit (A)
Output Short Circuit (A)
12
Time (25μs/Div)
is a registered trademark of Richtek Technology Corporation.
DS9199-11 April 2014
RT9199
Application Information
Consideration while designing the resistance of
voltage divider
Refer to the “Typical Application Circuit”. Make sure the
current sinking capability of pull-down NMOS is enough
for the chosen voltage divider to pull-down the voltage at
REFEN pin below 0.15V to shutdown the device.
As other linear regulator, dropout voltage and thermal issue
should be specially considered. Figure 7 shows the RDS(ON)
over temperature of RT9199. The minimum dropout voltage
could be obtained by the product of RDS(ON) and output
current. For thermal consideration, please refer to the
relative sections.
VREFEN
In addition, the capacitor CSS and voltage divider form the
low-pass filter. There are two reasons doing this design;
one is for output voltage soft-start while another is for
noise immunity.
RT9199
VOUT
REFEN
How to reduce power dissipation on Notebook PC
or the dual channel DDR SDRAM application?
R2
GND
In notebook application, using RichTek's Patent
Bus Terminator Topology” with choosing
RichTek's product is encouraged.
“ Distributed
Figure 6
RDS(ON) vs. Temperature
0.48
Distributed Bus Terminating Topology
Terminator Resistor
0.46
R0
VOUT
R2
R3
R4
REFEN
R5
BUS(2)
BUS(3)
BUS(4)
RT9199
R7
R8
R9
R(2N)
R(2N+1)
0.4
0.38
0.36
0.34
BUS(5)
0.32
BUS(6)
0.3
BUS(7)
0.28
R6
VOUT
0.42
R DS(ON) (Ω)
RT9199
VCNTL = 5V, VREFEN = 1V
0.44
BUS(0)
R1
BUS(1)
-50
BUS(8)
BUS(9)
VIN
VCNTL
R1
-25
0
25
50
75
100
125
Temperature (°C)
Figure 7
Input Capacitor and Layout Consideration
BUS(2N)
BUS(2N+1)
General Regulator
The RT9199 could also serves as a general linear regulator.
The RT9199 accepts an external reference voltage at
REFEN pin and provides output voltage regulated to this
reference voltage as shown in Figure 6, where
Place the input bypass capacitor as close as possible to
the RT9199. A low ESR capacitor larger than 470uF is
recommended for the input capacitor. Use short and wide
traces to minimize parasitic resistance and inductance.
Inappropriate layout may result in large parasitic inductance
and cause undesired oscillation between RT9199 and the
preceding power converter.
VOUT = VREFEN x R2/(R1+R2)
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RT9199
Ambient
Molding Compound
Gold Line
Thermal Consideration
RT9199 regulators have internal thermal limiting circuitry
designed to protect the device during overload conditions.
For continued operation, do not exceed absolute maximum
operation junction temperature 125°C. The power
dissipation definition in device is :
PD = (VIN - VOUT) x IOUT + VIN x IQ
The maximum power dissipation depends on the thermal
resistance of IC package, PCB layout, the rate of
surroundings airflow and temperature difference between
junction to ambient. The maximum power dissipation can
be calculated by following formula :
PD(MAX) = (TJ(MAX) − TA) / θJA
Where T J(MAX) is the maximum operation junction
temperature 125°C, TA is the ambient temperature and
the θJA is the junction to ambient thermal resistance. The
junction to ambient thermal resistance for SOP-8 package
(Exposed Pad) is 42.9°C/W, on standard JEDEC 51-7 (4
layers, 2S2P) thermal test board. The maximum power
dissipation at TA = 25°C can be calculated by following
formula :
Lead Frame
Die Pad
PCB
Case (Exposed Pad)
Figure 8. SOP-8 (Exposed Pad) Package Sectional
Drawing
RGOLD-LINE
RLEAD FRAME
RPCB
path 1
Junction
RDIE
RDIE-ATTACH RDIE-PAD
path 2
RPCB
Case
(Exposed Pad)
Ambient
RMOLDING-COMPOUND
path 3
Figure 9. Thermal Resistance Equivalent Circuit
PD(MAX) = (125°C − 25°C) / 42.9°C/W = 2.33W
Figure 8 shows the package sectional drawing of SOP-8
(Exposed Pad). Every package has several thermal
dissipation paths. As show in Figure 9, the thermal
resistance equivalent circuit of SOP-8 (Exposed Pad). The
path 2 is the main path due to these materials thermal
conductivity. We define the exposed pad is the case point
of the path 2.
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RT9199
Outline Information
H
A
M
J
B
F
C
I
D
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
4.801
5.004
0.189
0.197
B
3.810
3.988
0.150
0.157
C
1.346
1.753
0.053
0.069
D
0.330
0.508
0.013
0.020
F
1.194
1.346
0.047
0.053
H
0.170
0.254
0.007
0.010
I
0.050
0.254
0.002
0.010
J
5.791
6.200
0.228
0.244
M
0.400
1.270
0.016
0.050
8-Lead SOP Plastic Package
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RT9199
H
A
M
EXPOSED THERMAL PAD
(Bottom of Package)
Y
J
B
X
F
C
I
D
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
4.801
5.004
0.189
0.197
B
3.810
4.000
0.150
0.157
C
1.346
1.753
0.053
0.069
D
0.330
0.510
0.013
0.020
F
1.194
1.346
0.047
0.053
H
0.170
0.254
0.007
0.010
I
0.000
0.152
0.000
0.006
J
5.791
6.200
0.228
0.244
M
0.406
1.270
0.016
0.050
X
2.000
2.300
0.079
0.091
Y
2.000
2.300
0.079
0.091
X
2.100
2.500
0.083
0.098
Y
3.000
3.500
0.118
0.138
Option 1
Option 2
8-Lead SOP (Exposed Pad) Plastic Package
Richtek Technology Corporation
14F, No. 8, Tai Yuen 1st Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
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DS9199-11 April 2014