RT9186A/B
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DS9186AB-11 April 2011 www.richtek.com
Pin Configurations
Low Profile 500mA LDO with Enable and Power Good/Reset
Ordering Information
Features
zz
zz
z2.5V to 5.5V Wide Input Range
zz
zz
zGuaranteed 500mA Output Current
zz
zz
zLow 160mV Dropout at 500mA
zz
zz
z1.8V/2.5V/3.3V Preset Output Voltage Version with
Adjustable Range from 0.8V to 4.5V.
zz
zz
zReset Output with 6ms (typ.) Delay Time
zz
zz
zPower Good Output
zz
zz
zLow 190μμ
μμ
μA Ground Pin Current
zz
zz
z0.1μμ
μμ
μA Shutdown Current
zz
zz
zThermal and Over Current Protection
zz
zz
zRoHS Compliant and 100% Lead (Pb)-Free
Applications
zNotebook Computer
zPDAs/SHDs
zPCMCIA/Cardbus Card Product
zMobile Phone
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
(TOP VIEW)
RT9186A
RT9186B
General Description
The RT9186 is a low-dropout linear regulator providing up
to 500mA load current with 160mV dropout. It is especially
designed for the application of portable and smart handheld
device.
The RT9186 operates from 2.5V to 5.5V supply. The
internal P-MOSFET pass transistor allows the regulator
to work with 190μA low quiescent current. Its preset output
voltage version covers the most frequently used values,
including 1.8V/2.5V/3.3V. Output voltage can also be
adjusted via the ADJ pin for those other than the preset
values.
With only 0.1μA required in the shut down mode, one
enable pin is able to control output on/off. RT9186A
contains PGOOD function. On the other hand, RT9186B
contains RST function with 6ms (typ.) time delay.
MSOP-8 VDFN-8L 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.
MSOP-8 VDFN-8L 3x3
9
7
6
5
1
2
3
4
8
VIN
EN
VIN
VOUT
VOUT
ADJ
GND
PGOOG
9
7
6
5
1
2
3
4
8
VIN
EN
VIN
VOUT
VOUT
ADJ
GND
RST
5
6
7
8
4
3
2
VIN VOUT
VOUT
ADJ
GND
EN
PGOOD
VIN
VIN
EN
VIN
5
6
7
8
4
3
2
VOUT
VOUT
ADJ
GND
RST
RT9186A/B
Package Type
F : MSOP-8
QV : VDFN-8L 3x3 (V-Type)
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
−
Output Voltage
Default : Adjustable
18 : 1.8V
25 : 2.5V
33 : 3.3V
A : Power Good Function
B : Reset Function
RT9186A/B
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DS9186AB-11 April 2011www.richtek.com
Typical Application Circuit
Figure 1. Fixed Voltage Regulator
Figure 2. Adjustable Voltage Regulator
Note1 : R2 should be less than 80k to ensure regulation.
Note2 : X5R or X7R input capacitor ¡Ù1 μμ
μμ
μF is recommended for output stability.
Pin Description
Pi n Name Pin Function
VIN Power Input Voltage.
VOUT Output Voltage.
GND Ground.
EN Chip Enable (Active-High). There should be a pull low resistor 100kΩ connected to GND
when the control signal is floating.
PGOOD Power Good Indicator. (RT9186A).
RST Open-Drain Active-Low Reset Output. Connect a 100kΩ to VOUT to obtain output voltage.
In shutdown the RST output is low. (RT9186B).
ADJ Output Voltage Setting. Connect to GND for Fixed output voltage model.
)
R
R
(1 0.8 V
2
1
OUT +=
VIN
EN
GND
VOUT
ADJ
PGOOD/
RST
RT9186A/B
VOUT
COUT
CIN
VIN
R1
R2
TO μC
100k
10uF
1uF
Chip Enable
VIN
EN
GND
VOUT
ADJ
PGOOD/
RST
RT9186A/B
VOUT
COUT
CIN
VIN
100k 10uF
TO μC
1uF
Chip Enable
RPGOOD/RST
RT9186A/B
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DS9186AB-11 April 2011 www.richtek.com
Function Block Diagram
-RT9186A-
-RT9186B-
Thermal
Shutdown
VOUT
Shutdown
Logic
EN
GND
Output Mode
Comparator
+
-
ADJ
VIN
Error
Amplifier
+
-
0.8V
Reference
Current Limit
Sensor +
-
100mV
Delay
Timer
+
-
RST
80%
Reference
Thermal
Shutdown
VOUT
Shutdown
Logic
EN
GND
Output Mode
Comparator
+
-
ADJ
VIN
Error
Amplifier
+
-
0.8V
Reference
Current Limit
Sensor +
-
100mV
+
-
PGOOD
80%
Reference
RT9186A/B
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DS9186AB-11 April 2011www.richtek.com
Timing Diagram
Recommended Operating Conditions (Note 4)
zInput Voltage ---------------------------------------------------------------------------------------------------------- 2.5V to 5.5V
zJunction Temperature Range -------------------------------------------------------------------------------------- −40°C to 125°C
zAmbient Temperature Range -------------------------------------------------------------------------------------- −40°C to 85°C
Absolute Maximum Ratings (Note 1)
zInput Voltage ---------------------------------------------------------------------------------------------------------- 7V
zStorage Temperature Range --------------------------------------------------------------------------------------- −65°C to 150°C
zLead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------- 260°C
zPower Dissipation, PD @ TA = 25°C
MSOP-8 --------------------------------------------------------------------------------------------------------------- 0.625W
VDFN-8L 3x3 ---------------------------------------------------------------------------------------------------------- 0.952W
zPackage Thermal Resistance (Note 2)
MSOP-8, θJA ---------------------------------------------------------------------------------------------------------- 160°C/W
VDFN-8L 3x3, θJA ---------------------------------------------------------------------------------------------------- 105°C/W
zJunction Temperature ----------------------------------------------------------------------------------------------- 150°C
zESD Susceptibility (Note 3)
HBM (Human Body Mode) ----------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ------------------------------------------------------------------------------------------------ 200V
VIN
VOUT
PGOOD Function
(RT9186A)
80% of VOUT (Normal)
Delay Time (typ.) 6ms
Reset function
(RT9186B)
RT9186A/B
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DS9186AB-11 April 2011 www.richtek.com
Electrical Characteristics
(VIN = VOUT(NOM) + 500mV or VIN = +2.5V (whichever is greater), TA = 25°C, unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Unit
General Specification
Input Under Voltage Lock-Out VUVLO 2.0 2.3 2.4 V
Output V oltage Acc uracy
(Preset Mode) ΔVOUT I
OUT = 1mA to 500mA −3 0 3 %
Adjustable Output Voltage Range VOUT_ADJ 0.8 -- 4.5 V
ADJ Pin Voltage VAD J 0.784 0.8 0.816 V
ADJ Input Bias Current IADJ V
AD J = +0.8V -- 10 100 nA
Short Circuit Current Limit ILIM V
OUT = 0V 0.9 1.4 2.0 A
Quiescent Current (Note 5) IQ I
OUT = 0mA -- 190 250 μA
VOUT = 2.5V -- 200 330
Dropout Voltage (Note 6) VDROP I
OUT = 500mA VOUT = 3.3V -- 160 220 mV
Line Regulation ΔVLINE VOUT + 0.1V < VIN < 5.5V
IOUT = 5mA -- 0.02 0.125 %/V
Load Regulation (Note 7) ΔVLOAD I
OUT = 1mA to 500mA -- 21 40 mV
Chip Enable
Standby Current ISTBY V
IN = 5.5V -- 0.1 2 μA
Logic-Low Voltage VEN L V
IN = 2.5V -- -- 0.7
EN Threshold Logic-High Voltage VEN H V
IN = 5.5V 1.6 -- -- V
EN Input Bias Current IEN V
CE = 5.5V -- 20 100 nA
Reset
Reset Output Low Voltage VOL Reset Output Sinking 2mA -- 50 100 mV
Output High Leakage Current VRST = 5V -- -- 100 nA
Threshold to Output Voltage Rising edge, referred to VOUT 77 80 83 %
Reset Delay Time TDELAY Rising edge of VOUT to VRST 0.7 6 8 ms
Power Good
PGOOD Output Low Voltage PGOOD Output sinking 2mA -- 50 100 mV
Output High Leakage Current VPGOOD = 5V -- -- 100 nA
Threshold to Output Voltage Rising edge, referred to VOUT 77 80 83 %
Thermal Protection
Thermal Shutdown Temperature TSD -- 160 -- °C
Thermal Shutdown Hysteresis ΔTSD -- 30 -- °C
RT9186A/B
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DS9186AB-11 April 2011www.richtek.com
Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for
stress ratings. 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 for extended
periods may remain possibility to affect device reliability.
Note 2. θJA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board (single-layer,
1S) of JEDEC 51-3 thermal measurement standard.
Note 3. Devices are ESD sensitive. Handling precaution is highly recommended.
Note 4. The operating conditions beyond the recommended range is not guaranteed.
Note 5. Quiescent, or ground current, is the difference between input and output currents. It is defined by IQ = IIN - IOUT under
no load condition (IOUT = 0mA). The total current drawn from the supply is the sum of the load current plus the ground
pin current.
Note 6. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
Note 7. Regulation is measured at constant junction temperature by using a 20ms current pulse. Devices are tested for load
regulation in the load range from 1mA to 300mA and 500mA respectively.
RT9186A/B
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DS9186AB-11 April 2011 www.richtek.com
Typical Operating Characteristics
CIN = 1uF(X7R Ceramic), COUT = 10uF(Y5V Cera mic), TA = 25°°
°°
°C, unle ss otherwise specified.
Short Circuit Current Limit vs. Temperature
1.40
1.45
1.50
1.55
1.60
-50-25 0 25 50 75100125
Temperature
Short Circuit Current Limit (A)1
VEN = VIN = 3.3V
VOUT = 1.8V
RL = 0 Ω
(°C)
Time (1 ms/Div)
VEN = VIN = 3.3V
VOUT = 1.8V
RL = 0 Ω
Short Circuit Current Limit (A)
2
1.5
1
0.5
0
Short Circuit Current Limit
Input Voltage vs. Output Voltage
0
0.5
1
1.5
2
2.5
3
3.5
2 2.7 3.4 4.1 4.8 5.5
Input Voltage (V)
Output Voltage (V)
No Load
ILOAD = 500mA
VOUT = 3.3V
Output Voltage vs. Input Voltage Output Voltage vs. Temperature
1.7
1.9
2.1
2.3
2.5
2.7
2.9
3.1
3.3
-50-250 255075100125
Temperature
Output Volatge (V)
VOUT = 2.5V
VOUT = 1.8V
VOUT = 3.3V
VEN = VIN = 5V
RL =
(°C)
∞
Quiescent Current vs. Temperature
130
150
170
190
210
230
-50 -25 0 25 50 75 100 125
Temperature
Quiescent Current (uA) 1
VEN = VIN = 3.3V
VOUT = 1.8V
RL =
(°C)
∞
Dropout Voltage vs. Load Current
0
50
100
150
200
250
0 100 200 300 400 500
Load Current (mA)
Dropout Voltage (mV)
VOUT = 2.5V TJ = 125°C
TJ = −40°C
TJ = 25°C
RT9186A/B
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DS9186AB-11 April 2011www.richtek.com
Line Transient Response
Input
Voltage(V)
Output Voltage
Deviation(mV)
20
0
-20
4
3
ILOAD = 100mA
VOUT = 1.8V
Without CIN
Time (50us/Div)
Load Transient Response
Time (50us/Div)
Load
Current (A)
20
0
-20
0.4
0.2
0VOUT = 1.8V
VIN = 3.3V
ILOAD = 1 to 250mA
Output Voltage
Deviation(mV)
Reset Response
Time (10ms/Div)
VIN = VEN (2V/Div)
VOUT (2V/Div)
ILOAD = 50mA
VOUT = 3.3V
Without CIN
VRST (2V/Div)
Reset Response
Time (1ms/Div)
VEN (2V/Div)
VOUT (2V/Div)
VRST (2V/Div)
ILOAD = 50mA
VOUT = 3.3V
VIN = 3.8V
Shutdown Response
Time (100us/Div)
4
2
0
EN Voltage
(V)
Output
Voltage (V)
3
2
1
0
ILOAD = 500mA, VOUT = 3.3V, VIN = 5V
PGOOD Response
Time (1ms/Div)
VEN (2V/Div)
VOUT (2V/Div)
VPGOOD (2V/Div)
ILOAD = 50mA
VOUT = 3.3V
VIN = 3.8V
RT9186A/B
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DS9186AB-11 April 2011 www.richtek.com
Application Information
Capacitor Selection and Regulator Stability
Careful selection of the external capacitors for RT9186 is
highly recommended in order to remain high stability and
performance.
Regarding the Input capacitor, connecting an X7R or X5R
ceramic capacitor which is ¡Ù1μF between input and
ground is a must. Distance less than 1 cm between input
pin and ground of RT9186 is recommended to avoid any
unstability. With larger value of capacitor adding on lower
ESR could result in better performance for both PSRR
and line transient response.
Regarding the output capacitor, connecting a10μF
capacitor between output and ground is a must. Any
capacitor is acceptable only with a highlight of relation
between ESR region and Load current, shown in below.
Output capacitor with larger capacitance can reduce noise
and improve load transient response, stability, and PSRR.
The same as Input capacitor, distance less than 1 cm
between output pin and ground of RT9186 is recommended
to avoid any unstability.
Region of Stable COUT ESR vs. Load Current
0.01
0.10
1.00
10.00
100.00
0 100 200 300 400 500
Load Current (mA)
COUT ESR (Ω)
Instable
Instable
Stable
1
10
100 VIN = 3V
0.01
0.10
Input-Output (Dropout) V oltage
A regulator’s minimum input-to-output voltage differential
(dropout voltage) determines the lowest usable supply
voltage. In battery-powered systems, this determines the
useful end-of-life battery voltage. Because the device uses
a P-MOSFET, its dropout voltage is a function of drain-to-
source on-resistance, RDS(ON), multiplied by the load
current:
VDROPOUT = VIN -VOUT = RDS(ON) IOUT
Over-Current and Short-Circuit Protection
The RT9186 continuously monitors output current to
provide maximum safety. In the event of output over current
or short-circuit, over-current protection function will activate
and override the voltage regulation function to limit output
current at 1.4A typically. Large power dissipation at this
condition may cause chip temperature to raise and trigger
the over temperature protection if over-current or short-
circuit is not removed in a short time
Power Good and Reset
The power good and the reset output is an open-drain
output. Connect an 100kΩ pull up resistor to VOUT to obtain
an output voltage. The power good will output high
immediately after the output voltage arrives 80% of normal
output voltage. In the same situation, the reset will output
high with 6ms delay time. See Timing Diagram and Typical
Operating Characteristics.
Adjustable Operation
The output voltage of RT9186 is adjustable from 0.8V to
4.5V by an external voltage divider as shown in Typical
Application Circuit Figure 2. The value of R2 should be
less than 80kΩ to ensure regulation.
Chip Enable Operation
Pull the EN pin low to drive the device into shutdown mode.
At the same time, pin 3 (PGOOD/RST) is pulled low. During
shutdown mode, the standby current drops to 0.1μA (typ).
The output voltage decay rate is determined by the external
capacitor and load current. Drive the EN pin high to turn
on the device again.
RT9186A/B
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DS9186AB-11 April 2011www.richtek.com
Reverse Current Path
The P-MOSFET pass element of RT9186 has an
inherendiode connected between the regulator input and
output as shown in Figure 3. The inherent diode will be
forward biased and conduct an unlimited current if VOUT is
sufficiently higher than VIN. a Schottky diode is
recommended connecting parallel with the inherent diode
in the application where output voltage may be higher than
input voltage as shown in Figure 4. This Schottkly will
clamp the forward bias voltage to 0.3V and conduct the
possible current to protect the RT9186 from damage by
unlimited current.
VIN VOUT
VIN VOUT
Figure 3. Inherent Diode of P-MOSFET Pass Transistor
Figure 4. Schottkly Diode Parallel with The Ingerent Diode
Thermal Considerations
Thermal protection limits power dissipation in
RT9186A/B. When the operation junction temperature
exceeds 160°C, the OTP circuit starts the thermal
shutdown function and turns the pass element off. The
pass element turn on again after the junction temperature
cools by 30°C.
For continuous 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 Figure 5
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 TJ(MAX) is the maximum operation junction
temperature 125°C, TA is the ambient temperature and the
θJA is the junction to ambient thermal resistance.
For recommended operating conditions specification of
RT9186A/B, where TJ(MAX) is the maximum junction
temperature of the die (125°C) and TA is the maximum
ambient temperature. The junction to ambient thermal
resistance θJA is layout dependent. For VDFN-8L 3x3
package, the thermal resistance θJA is 105°C/W on the
standard JEDEC 51-3 single-layer 1S thermal test board
and 70°C/W on the standard JEDEC 51-7 4-layers 2S2P
thermal test board. The maximum power dissipation at
TA = 25°C can be calculated by following formula :
PD(MAX) = ( 125°C - 25°C ) / 105 = 0.952W for single-layer
1S board
PD(MAX) = ( 125°C - 25°C ) / 70 = 1.428W for 4-layers
2S2P board
The maximum power dissipation depends on operating
ambient temperature for fixed TJ(MAX) and thermal
resistance θJA. For RT9186A/B packages, the Figure 5
of derating curves allows the designer to see the effect of
rising ambient temperature on the maximum power
allowed.
0
250
500
750
1000
1250
1500
0255075100125
Ambient Temperature (°C)
Maximum Power Dissipation (mW)
DFN-8L at 4-Layers PCB
MSOP-8 at 1-Layers PCB
DFN-8L at 1-Layers PCB
RT9186A/B
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DS9186AB-11 April 2011 www.richtek.com
PCB Layout
Good board layout practices must be used or instability
can be induced because of ground loops and voltage drops.
The input and output capacitors MUST be directly
connected to the input, output, and ground pins of the
device using traces which have no other currents flowing
through them.
The best way to do this is to layout CIN and COUT near the
device with short traces to the VIN, VOUT, and ground pins.
The regulator ground pin should be connected to the
external circuit ground so that the regulator and its
capacitors have a “single point ground”.
It should be noted that stability problems have been seen
in applications where “vias” to an internal ground plane
were used at the ground points of the device and the input
and output capacitors. This was caused by varying ground
potentials at these nodes resulting from current flowing
through the ground plane. Using a single point ground
technique for the regulator and it’s capacitors fixed the
problem. Since high current flows through the traces going
into VIN and coming from VOUT, Kelvin connect the capacitor
leads to these pins so there is no voltage drop in series
with the input and output capacitors.
Optimum performance can only be achieved when the
device is mounted on a PC board according to the
MSOP-8 Board Layout diagram.
MSOP-8 Board Layout
GND
SET
EN
+
VOUT
VIN
GND
PGOOD
/ RST
+
RT9186A/B
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DS9186AB-11 April 2011www.richtek.com
Outline Dimension
L
D
EE1
e
A
bA1 A2
8-Lead MSOP Plastic Package
Dimension s In Millimeters Dimension s In Inches
Symbol Min Max Min Max
A 0.810 1.100 0.032 0.043
A1 0.000 0.150 0.000 0.006
A2 0.750 0.950 0.030 0.037
b 0.220 0.380 0.009 0.015
D 2.900 3.100 0.114 0.122
e 0.650 0.026
E 4.800 5.000 0.189 0.197
E1 2.900 3.100 0.114 0.122
L 0.400 0.800
0.016 0.031
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DS9186AB-11 April 2011 www.richtek.com
RT9186A/B
Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit
design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be
guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.
Richtek Technology Corporation
Headquarter
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Richtek Technology Corporation
Taipei Office (Marketing)
5F, No. 95, Minchiuan Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8862)86672399 Fax: (8862)86672377
Email: marketing@richtek.com
Dim e nsion s In Mi ll imet e rs Dimens ions In I nche s
Symbol Min Max Min Max
A 0.800 1.000 0.031 0.039
A1 0.000 0.050 0.000 0.002
A3 0.175 0.228 0.007 0.009
b 0.200 0.300 0.008 0.012
D 2.950 3.050 0.116 0.120
D2 2.250 2.350 0.089 0.093
E 2.950 3.050 0.116 0.120
E2 1.450 1.550 0.057 0.061
e 0.650 0.026
L 0.425 0.525
0.017 0.021
V-Type 8L DFN 3x3 Package
D
1
E
A
A1 A3
D2
E2
L
be
