ETC TD5820

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DATASHEET
2A Low Dropout Regulator with Enable
TD5820A/B
汪工　ＴＥＬ：１３８２８７１９４１０　ＱＱ：１９２９７９４２３８
General Description Features The TD5820 is a high performance positive voltage
regulator designed for use in applications requiring very
low Input voltage and very low dropout voltage at up to 2
amps. It operates with a VIN as low as 1.6V and VPP
voltage 5V with output voltage programmable as low as
0.8V. The TD5820 features ultra low dropout, ideal for
applications where VOUT is very close to VIN.
Additionally, the TD5820 has an enable pin to further
reduce power dissipation while shutdown. The TD5820
provides excellent regulation over variations in line,
load and temperature. The TD5820 provides a power OK
signal to indicate if the voltage level of VO reaches
92% of its rating value.
The TD5820 is available in the power SOP-8 PP package. It is available with 1.2V, 1.5V, 1.8V and 2.5V internally preset outputs that are also adjustable using
external resistors.
z
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Adjustable Output Low to 0.8V
Input Voltage as Low as 1.6V and VPP Voltage 5V
240mV Dropout @ 2A
Over Current and Over Temperature Protection
Enable Pin
Low Reverse Leakage (Output to Input )
Power SOP8 –PP Packages with Thermal Pad
±2% Output Voltage
VO Power OK Signal
1.2V, 1.5V, 1.8V, 2.5V Options and Adjustable
Externally Using Resistors
VO Pull Low Resistance when Disable
Applications z
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Motherboards
Peripheral Cards
Network Cards
Set Top Boxes
Notebook Computers Package Types Figure 1. Package Types of TD5820A/B/E/F December, 20, 2009. Techcode Semiconductor Limited www.tongchuangwei.com
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Pin Assignments PIN
NAME
1
PGOOD
Assert high once VO reaches 92% of
its rating voltage. Open-drain output.
2
EN
Enable Input. (Active High)
3
VIN
Input voltage. Large bulk capacitance
should be placed closely to this pin. A
10µF ceramic capacitor is
recommended at this pin.
4
VDD
Input voltage for controlling circuit.
5
NC
Not connected.
6
VOUT
The power output of the device. A pull
low resistance exists when deactivate
device by VEN.
7
ADJ
This pin, TD5820A/B when grounded,
sets the output voltage by the internal
feedback resistors. If external
feedback resistors are used, the
output voltage will be
VO = 0.8(R1+R2)/R2 Volts.
8
GND
Reference ground.
SOP8‐PP TD5820A/B
2A Low Dropout Regulator with Enable
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TD5820A/B
2A Low Dropout Regulator with Enable
Ordering Information TD5820 A/B □ Circuit Type Output Versions
Blank：Adj
12：1.2V
15：1.5V
18：1.8V
25：2.5V
Enable Pin Function&ADJ Pin Function
A:Enable Pin Internal Pull High, Active High
ADJ Pin grounded output voltage by the internal feedback resistors
B:Enable Pin Internal Pull Low, Active High
ADJ Pin grounded output voltage by the internal feedback resistors
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TD5820A/B
2A Low Dropout Regulator with Enable
Functional Block Diagram Figure2:Functional Block Diagram of TD5820A/B Absolute Maximum Ratings Note1: Stresses greater than those listed under Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operation is not implied. Exposure to absolute maximum rating conditions for extended
periods may affect reliability.
Parameter
Rating
Unit
VDD Supply Voltage (VDD to GND)
-0.3 ~ 6
V
VIN Supply Voltage (VIN to GND)
-0.3 ~ 6
V
VOUT to GND Voltage
-0.3 ~ VIN+0.3
V
PGOOD to GND Voltage
-0.3 ~ 7
V
EN,ADJ to GND Voltage
-0.3 ~ VCNTL+0.3
V
Power Dissipation
Internally Limited
Maximum Junction Temperature
ºC
Storage Temperature Range
150
-65°C ≤TJ ≤ +150
Reflow Temperature (soldering, 10sec)
260
ºC
Thermal Resistance Junction to Ambient
50
°C/W
Thermal Resistance Junction to Case
20
°C/W
Operating Temperature Range
-40 to +125
ºC
Storage Temperature
-65 to +150
ºC
Lead Temperature (Soldering, 10 sec)
260
ºC
ESD Rating (Human Body Model)
2000
V
ºC
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TD5820A/B
2A Low Dropout Regulator with Enable
Recommended Operating Conditions Symbol
Parameter
Range
Unit
VDD
VCNTL Supply Voltage
3.0 ~ 5.5
V
VIN
VIN Supply Voltage
1.2 ~ 5.5
V
VOUT
VOUT Output Voltage (when VCNTL-VOUT>1.7V)
0.8 ~ VIN – VDROP
V
IOUT
VOUT Output Current
0~2
A
R2
ADJ to GND
1k ~ 24k
Ω
COUT
VOUT Output Capacitance
IOUT = 2A at 25% nominal VOUT
8~770
IOUT = 1A at 25% nominal VOUT
8~1400
IOUT = 0.5A at 25% nominal VOUT
8~1700
uF
ESRCOUT
ESR of VOUT Output Capacitor
0 ~ 200
mΩ
TA
Ambient Temperature
-40 ~ 85
ºC
TJ
Junction Temperature
-40 ~ 125
ºC
Electrical Characteristics Note:Refer to the typical application circuits. These specifications apply over VCNTL=5V,
vIN=1.8v,
VOUT=1.2V, and TA= -40 ~ 85oC, unless otherwise specified.
Typical values are at TJ=25oC.
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
POR Threshold
2.4
2.7
3
V
POR Hysteresis
0.15
0.2
-
V
VTH_ADJ
Adjustable Pin Threshold
IOUT=1mA
-
0.2
0.4
V
VADJ
Reference Voltage
IOUT=1mA
0.784
0.8
0.816
V
ΔVOUT
Fixed Output Voltage Range
-2
0
+2
%
ΔVLINE_IN
Line Regulation(VIN)
VIN=VOUT+0.5V TO 5V
IOUT=1mA
-
0.2
0.6
%
ΔVLOAD
Load Regulation
VIN=VOUT+1V
IOUT=1mA TO 2A
-
0.1
1
%
VDROP
Dropout Voltage
IOUT= 2A
150
250
mV
IQ
Quiescent Current
VDD=5.5V
-
0.6
1.2
mA
ILIM
Current Limit
2.8
3.2
A
0.5
1.8
A
0.6
A
Short Circuit Current
VOUT<0.2V
In-rush Current
COUT=10uF,Enable Start-up
VOUT Pull-Low Resistance
VEN=0V
-
150
-
Ω
Chip Enable
IEN
EN Input Bias Current
VEN=0V
12
ISHDN
VDD Shutdown Current
TD5820A
-
10
20
TD5820B
-
-
1
uA
uA
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TD5820A/B
2A Low Dropout Regulator with Enable
VENL
EN Threshold
VENH
Logic-Low Voltage
-
-
0.2
V
Logic-High Voltage
1.2
-
-
90
93
%
10
-
%
0.2
0.4
V
0.5
1.5
5
mS
Power Good
PGOOD Rising Threshold
PGOOD Hysteresis
PGOOD Sink Capability
3
IPGOOD=10mA
PGOOD Delay
Thermal Protection
TSD
Thermal Shutdown Temperature
-
160
-
ºC
ΔTSD
Thermal Shutdown Hysteresis
-
30
-
ºC
-
110
-
ºC
Thermal Shutdown Temperature
Fold-back
VOUT<0.4V
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2A Low Dropout Regulator with Enable
DATASHEET
TD5820A/B
Typical Operating Characteristics Current-Limit vs.
Junction Temperature
Short Current-Limit vs.
Junction Temperature
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2A Low Dropout Regulator with Enable
TD5820A/B
Typical Operating Characteristics(Cont.) Dropout Voltage vs. Output Current
Droput Voltage vs. Output Current
Droput Voltage vs. Output Current
Droput Voltage vs. Output Current
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2A Low Dropout Regulator with Enable
DATASHEET
TD5820A/B
Typical Operating Characteristics(Cont.) Droput Voltage vs. Output Current
Reference Voltage vs.
Junction Temperature
VCNTL Power Supply Rejection
Ratio (PSRR)
VIN Power Supply Rejection
Ratio (PSRR)
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TD5820A/B
2A Low Dropout Regulator with Enable
OperatingWaveforms Refer to the typical application circuit. The test condition is VIN=1.5V, VCNTL=5V, VOUT=1.2V, TA= 25oC unless otherwise specified Power On
Power Off COUT=10μF, CIN=10μF, RL=0.6Ω/ TIME: 5ms/Div
COUT=10μF, CIN=10μF, RL=0.6Ω/ TIME: 10ms/Div
CH1: VCNTL, 5V/Div, DC/CH2: VIN, 1V/Div, DC CH1: VCNTL, 5V/Div, DC/CH2: VIN, 1V/Div, DC CH3: VOUT, 1V/Div, DC/CH4: VPOK, 5V/Div, DC CH3: VOUT, 1V/Div, DC/CH4: VPOK, 5V/Div, DC Load Transient Response
Over Current Protection IOUT=10mA to 2A to 10mA (rise / fall time = 1μs) COUT=10μF, CIN=10μF COUT=10mF, CIN=10mF, IOUT=1A to 3.4A CH1: VOUT, 50mV/Div, AC/CH4: IOUT, 1A/Div, DC/ TIME: 20μs/Div CH1: VOUT, 1V/Div, DC/ CH4: IOUT, 1A/Div, DC/ TIME: 0.2ms/Div December, 20, 2009. Techcode Semiconductor Limited www.tongchuangwei.com
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2A Low Dropout Regulator with Enable
TD5820A/B
OperatingWaveforms(Cont.) Refer to the typical application circuit. The test condition is VIN=1.5V, VCNTL=5V, VOUT=1.2V, TA= 25oC unless otherwise specified Shutdown Enable
COUT=10mF, CIN=10mF, RL=0.6W/ TIME: 5us/Div COUT=10mF, CIN=10mF, RL=0.6W/ TIME: 0.5ms/Div CH1: VEN, 5V/Div, DC/CH2: VOUT, 1V/Div, DC CH1: VEN, 5V/Div, DC/CH2: VOUT, 1V/Div, DC CH3: VPOK, 5V/Div, DC/CH4: IOUT, 2A/Div, DC CH3: VPOK, 5V/Div, DC/CH4: IOUT, 2A/Div, DC December, 20, 2009. Techcode Semiconductor Limited www.tongchuangwei.com
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2A Low Dropout Regulator with Enable
DATASHEET
TD5820A/B
Typical Application Circuit Figure3:Fixed Voltage Regulator Application Circuit of TD5820A/B Figure4:Adjustable Voltage Regulator Application Circuit of TD5820A/B December, 20, 2009. Techcode Semiconductor Limited www.tongchuangwei.com
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2A Low Dropout Regulator with Enable
TD5820A/B
Function Description Power­On­Reset Short Current­Limit Protection A Power-On-Reset (POR) circuit monitors both of supply
voltages on VCNTL and VIN pins to prevent wrong logic
controls. The POR function initiates a soft-start process
after both of the supply voltages exceed their rising POR
voltage thresholds during powering on. The POR
function also pulls low the POK voltage regardless of the
output status when one of the supply voltages falls below
its falling POR voltage threshold.
The short current-limit function reduces the current-limit
level down to 0.8A (typical) when the voltage on FB pin
falls below 0.2V (typical) during current overload or
shortcircuit conditions.
The short current-limit function is disabled for successful
start-up during soft-start.
Internal Soft­Start An internal soft-start function controls rise rate of the
output voltage to limit the current surge during start-up.
The typical soft-start interval is about 0.6ms.
Output Voltage Regulation An error amplifier working with a temperature
compensated 0.8V reference and an output NMOS
regulates output to the preset voltage. The error amplifier
is designed with high bandwidth and DC gain provides
very fast transient response and less load regulation. It
compares the reference with the feedback voltage and
amplifies the difference to drive the output NMOS which
provides load current from VIN to VOUT.
Current­Limit Protection The TD5820 monitors the current flowing through the
output NMOS and limits the maximum current to prevent
load andTD5820 from damages during current overload
conditions. Thermal Shutdown A thermal shutdown circuit limits the junction
temperature of TD5820. When the junction temperature
exceeds +170 ºC, a thermal sensor turns off the output
NMOS, allowing the device to cool down. The regulator
regulates the output again through initiation of a new
soft-start process after the junction temperature cools by
50oC, resulting in a pulsed output during continuous
thermal overload conditions. The thermal shutdown is
designed with a 50 ºC hysteresis to lower the average
junction temperature during continuous thermal overload
conditions, extending lifetime of the device.
For normal operation, the device power dissipation
should be externally limited so that junction temperatures
will not exceed +125 ºC.
Enable Control The TD5820A/B has a dedicated enable pin (EN).
TD5820A:A logic low signal applied to this pin shuts
down the output. Following a shutdown, a logic high
signal re-enables the output through initiation of a new
soft-start cycle. When left open, this pin is pulled up by
an internal current source (5μA typical) to enable normal
operation. It’s not necessary to use an external transistor
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2A Low Dropout Regulator with Enable
TD5820A/B
Function Description(Cont.) to save cost. TD5820B:A logic low signal applied to this pin shuts
down the output. Following a shutdown, a logic high
signal re-enables the output through initiation of a new
soft-start cycle. When left open, this pin is pulled up by
an internal current source (5μA typical) to turn off
operation. Power­OK and Delay The TD5820 indicates the status of the output voltage by
monitoring the feedback voltage (VADJ) on ADJ pin. As
the VADJ rises and reaches the rising Power-OK voltage
threshold(VTHPOK), an internal delay function starts to
work. At the end of the delay time, the IC turns off the
internal NMOS of the POK to indicate the output is ok. As
the VFB falls and reaches the falling Power-OK voltage
threshold, the IC turns on the NMOS of the POK ( after a
debounce time of 10ms typical ). December, 20, 2009. Techcode Semiconductor Limited www.tongchuangwei.com
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DATASHEET
2A Low Dropout Regulator with Enable
TD5820A/B
Application Information Power Sequencing The power sequencing of VIN and VDD is not necessary
to be concerned. However, do not apply a voltage to
VOUT for a long time when the main voltage applied at
VIN is not present. The reason is the internal parasitic
diode from VOUT to VIN conducts and dissipates power
without protections due to the forward-voltage.
Output Capacitor The TD5820 requires a proper output capacitor to
maintain stability and improve transient response. The
output capacitor selection is dependent upon ESR
(equivalent series resistance) and capacitance of the
output capacitorover the operating temperature. Ultra-low-ESR capacitors (such as ceramic chip
capacitors) and low-ESR bulk capacitors (such as solid
tantalum, POSCap, and Aluminum electrolytic
capacitors) can all be used as output capacitors.
During load transients, the output capacitors which is
depending on the stepping amplitude and slew rate of
load current, are used to reduce the slew rate of the
current seen by the TD5820 and help the device to
minimize the variations of output voltage for good
transient response. For the applications with large
stepping load current, the low-ESR bulk capacitors are
normally recommended.
Decoupling ceramic capacitors must be placed at the
load and ground pins as close as possible and the
impedance of the layout must be minimized. December, 20, 2009. Techcode Semiconductor Limited www.tongchuangwei.com
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DATASHEET
2A Low Dropout Regulator with Enable
TD5820A/B
Application Information(Cont.) Input Capacitor Setting The Output Voltage TheTD5820 requires proper input capacitors to supply
current surge during stepping load transients to prevent
the input voltage rail from dropping. Because the
parasitic inductor from the voltage sources or other bulk
capacitors to the VIN pin limit the slew rate of the surge
currents, more parasitic inductance needs more input
capacitance.
Ultra-low-ESR capacitors (such as ceramic chip
capacitors) and low-ESR bulk capacitors (such as solid
tantalum, POSCap, and Aluminum electrolytic capacitors
can all be used as an input capacitor of VIN. For most
applications, the recommended input capacitance of VIN
The output voltage is programmed by the resistor divider
connected to ADJ pin. The preset output voltage is
calculated by the following equation :
where R1 is the risistor connected from VOUT to ADJ
with Kelvin sensing connection and R2 is the risistor
connected from ADJ to GND. A bypass capacitor(C1)
may be connected with R1 in parallel to improve load
transient response and stability. is 10μF at least. However, if the drop of the input voltage
is not cared, the input capacitance can be less than
10μF. More capacitance reduces the variations of the
supply voltage on VIN pin. December, 20, 2009. Techcode Semiconductor Limited www.tongchuangwei.com
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2A Low Dropout Regulator with Enable
TD5820A/B
Layout Consideration(See Figure A) 1. Please solder the Exposed Pad on the system ground
pad on the top-layer of PCBs. The ground pad must have
wide size to conduct heat into the ambient air through the
system ground plane and PCB as a heat sink.
2. Please place the input capacitors for VIN and VCNTL
pins near the pins as close as possible for decoupling
high-frequency ripples.
3. Ceramic decoupling capacitors for load must be placed
near the load as close as possible for decoupling
high-frequency ripples.
4. To placeTD5820 and output capacitors near the load
reduces parasitic resistance and inductance for excellent
load transient response.
5. The negative pins of the input and output capacitors
and the GND pin must be connected to the ground plane
of the load.
6. Large current paths, shown by bold lines on the figure
1, must have wide tracks.
7. Place the R1, R2, and C1 (option) near the TD5820 as
close as to avoid noise coupling.
8. Connect the ground of the R2 to the GND pin by using
a dedicated track.
9. Connect the one pin of the R1 to the load for Kelvin
sensing.
10. Connect one pin of the C1 (option) to the VOUT pin
Thermal Consideration Refer to the figure B, the SOP-8PP is a cost-effective
package featuring a small size like a standard SOP-8 and
a bottom exposed pad to minimize the thermal resistance
of the package, being applicable to high current
applications. The exposed pad must be soldered to the
top-layer ground plane. It is recommended to connect the
top-layer ground pad to the internal ground plan by using
vias. The copper of the ground plane on the top-layer
conducts heat into the PCB and ambient air. Please
enlarge the area of the top-layer pad and the ground
plane to reduce the case-to-ambient resistance (θCA).
Figure B Figure A December, 20, 2009. Techcode Semiconductor Limited www.tongchuangwei.com
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2A Low Dropout Regulator with Enable
DATASHEET
TD5820A/B
Package Information SOP8-PP Package Outline Dimensions
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DATASHEET
2A Low Dropout Regulator with Enable
TD5820A/B
Design Notes
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