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RT9194
Low-Dropout Linear Regulator Controller with PGOOD Indication
General Description
The RT9194 is a low-dropout voltage regulator controller with a specific PGOOD indicating scheme, it acts as a power supervisor of the power regulated. The part could drive an external N-Channel MOSFET for various applications accordingly; especially, the part is operated with VCC power ranging from 4.5V to 13.5V. With such a topology, it's with advantages of flexible and cost-effective. The part comes to a small footprint package of SOT-23-6.
Features
4.5V to 13.5V Operation Voltage High Accuracy 2% 0.8V Voltage Reference Quick Transient Response Power Good Indicator with Delay Enable Control Compliant with Intel "Grantsdale Chipset Platform Design Guide" Specification Small Footprint Package SOT-23-6 RoHS Compliant and 100% Lead (Pb)-Free
Ordering Information
RT9194 Package Type E : SOT-23-6 Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard)
Applications
Special Designed for Intel (R) Grantsdale platform FSB_VTT power regulation Processor Power-Up Sequening Notebook and laptop PC Other Power regulation with Power Good indication.
Note : RichTek Pb-free and Green 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. 100%matte tin (Sn) plating.
Pin Configurations
(TOP VIEW)
VCC 6 1 DRI PGOOD 5 2 GND 4 3 FB
Marking Information
EN
For marking information, contact our sales representative directly or through a RichTek distributor located in your area, otherwise visit our website for detail.
SOT-23-6 Note : There is no pin1 indicator on top mark for SOT-23-6 type, and pin 1 will be lower left pin when reading top mark from left to right.
Typical Application Circuit
VCC VIN Ccc 1 2 3 EN GND FB RT9194 VCC DRI 6 5 4 RPGOOD CIN Q1 VOUT
Chip Enable
PGOOD
R1 PGOOD
COUT
R2
VOUT
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R1+ R2 = 0.8 x R2
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RT9194
Test Circuit
VCC 12V VIN
Chip Enable EN GND FB RT9194 VCC DRI
Ccc 1uF
CIN 100uF Q1 PHD3055 VOUT R1 1k COUT 100uF
100k PGOOD RPGOOD
PGOOD
VOUT
R1+ R2 = 0.8 x R2
R2 2k
Figure 1. Typical Test Circuit
VCC 12V
Chip Enable 5V EN GND VFB CFB VFB = 1V for current sink at DRI FB RT9194 VCC DRI
Ccc 1uF
A
VDRI
PGOOD
VFB = 0.6V for current source at DRI
Figure 2. DRI Source/Sink Current Test Circuit
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RT9194
Functional Pin Description
Pin Name EN GND FB PGOOD DRI VCC Pin No. 1 2 3 4 5 6 Pin Function Chip Enable (Active High) Ground Output Voltage Feedback Power Good Open Drain Output Driver Output Power Supply Input
Function Block Diagram
EN VCC Reference 0.8V Voltage 0.7V PGOOD 3ms Delay GND
+ + -
DRI
Driver
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-
FB
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RT9194
Absolute Maximum Ratings
(Note 1) Supply Input Voltage, VCC ------------------------------------------------------------------------------------------- 15V Enable Voltage --------------------------------------------------------------------------------------------------------- 7V Power Good Output Voltage ---------------------------------------------------------------------------------------- 7V Power Dissipation, PD @ TA = 25C SOT-23-6 ---------------------------------------------------------------------------------------------------------------- 0.4W Package Thermal Resistance SOT-23-6, JA ----------------------------------------------------------------------------------------------------------- 250C/W Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260C Junction Temperature ------------------------------------------------------------------------------------------------- 150C Storage Temperature Range ---------------------------------------------------------------------------------------- -65C to 150C ESD Susceptibility (Note 2) HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
(Note 3)
Supply Input Voltage, VCC ------------------------------------------------------------------------------------------- 4.5V to 13.5V Enable Voltage --------------------------------------------------------------------------------------------------------- 0V to 5.5V Junction Temperature Range ---------------------------------------------------------------------------------------- -40C to 125C Ambient Temperature Range ---------------------------------------------------------------------------------------- -40C to 85C
Electrical Characteristics
(VCC = 5V/12V, TA = 25C, unless otherwise specified)
Parameter VCC Operation Voltage Range POR Threshold POR Hysteresis VCC Supply Current Driver Source Current Driver Sink Current Reference Voltage (VFB) Reference Line Regulation (VFB) Amplifier Voltage Gain PSRR at 100Hz, No Load Power Good Rising Threshold Hysteresis Sink Capability Delay Time Falling Delay
Symbol
Test Conditions VCC input range VCC rising VCC falling VCC = 12V VCC = 12V, VDRI = 6V VCC = 12V, VDRI = 6V VCC = 12V, VDRI = 5V VCC = 4.5V to 15V VCC = 12V, no load VCC = 12V, no load VCC = 12V VCC = 12V VCC = 12V @ 1mA VCC = 12V VCC = 12V
Min 4.5 4.0 --5 5 0.784 --50
Typ -4.2 0.2 0.3 --0.8 3 70 --
Max 13.5 4.5 -0.8 --0.816 6 ---
Units V V V mA mA mA V mV dB dB
---1 --
90 15 0.2 3 15
--0.4 10 --
% % V ms us
To be Continued
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RT9194
Parameter Chip Enable EN Rising Threshold EN Hysteresis Standby Current VCC = 12V VCC = 12V VCC = 12V, VEN = 0V ---0.7 30 ---5 V mV uA Test Conditions Min Typ Max Units
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. Devices are ESD sensitive. Handling precaution recommended. Note 3. The device is not guaranteed to function outside its operating conditions.
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RT9194
Typical Operating Characteristics
Quiescent Current vs. Temperature
0.5
Feedback Voltage vs. Temperature
0.9
Refer to Test Circuit Figure 1
Quiescent Current (mA)
Feedback Voltage (V)
0.49
0.85
0.48
0.8
0.47
0.75
0.46
VIN = 1.5V, VCC = 12V, RPGOOD = 100k CIN = COUT = 100uF, R1 = 1k, R2 = 2k
0.45 -50 -25 0 25 50 75 100
VIN = 1.5V, VCC = 12V, RPGOOD = 100k CIN = COUT = 100uF, R1 = 1k, R2 = 2k
0.7 -50 -25 0 25 50 75 100
125
125
Temperature (C)
Temperature (C)
DRI Source Current vs. Temperature
60
DRI Sink Current vs. Temperature
30
Refer to Test Circuit Figure 2
DRI Source Current (mA)
DRI Sink Current (mA)
55
27 24 21 18 15
50
45
40
VFB = 1V, VCC = 12V, VDRI = 6V
35 -50 -25 0 25 50 75 100 125
VFB = 0.6V, VCC = 12V, VDRI = 6V
12 -50 -25 0 25 50 75 100 125
Temperature (C)
Temperature (C)
Sink Current vs. DRI Voltage
25
4
PGOOD Delay Time vs. Temperature
Refer to Test Circuit Figure 2 Refer to Test Circuit Figure 1
50 75 100 125
PGOOD Delay Time (ms)
20
3.5
VIN = 1.5V, VCC = 12V RPGOOD = 100k R1 = 1k, R2 = 2k
Sink Current (mA)
15
3
10
2.5
5
2
TA = 25C
0 0 0.5 1 1.5 2 2.5 3
1.5 -50 -25 0 25
DRI Voltage (V)
Temperature (C)
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Refer to Test Circuit Figure 2
Refer to Test Circuit Figure 1
RT9194
PGOOD Delay Time
VCC = 12V, CIN = COUT = 100uF, ILOAD = 100mA
PGOOD Delay Time
Refer to Test Circuit Figure 1 Refer to Test Circuit Figure 1 Refer to Test Circuit Figure 1 Refer to Test Circuit Figure 1
VCC = 12V, ILOAD = 1A CIN = COUT = 100uF
V OUT ILoad (A) VPGOOD
VOUT VPGOOD
VEN (V)
VEN (V)
Time (500us/Div)
Time (500us/Div)
PGOOD Off
Refer to Test Circuit Figure 1
V OUT
Enable Threshold Voltage vs. Temperature
1
Enable Threshold Voltage (V)
VCC = 12V CIN = COUT = 100uF
0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6
VIN = 1.5V, VCC = 12V, RPGOOD = 100k CIN = COUT = 100uF, R1 = 1k, R2 = 2k Turn on
ILoad (A)
Turn off
VPGOOD VEN (V)
Time (50us/Div)
-50
-25
0
25
50
75
100
125
Temperature (C)
Load Transient Response
Refer to Test Circuit Figure 1 FB Voltage Deviation (mV)
VIN = 2.5V, VOUT = 1.2V CIN = COUT = 100uF 20 0 -20
Line Transient Response
FB Voltage Deviation (mV)
VIN = 1.5V to 2.5V, ILOAD = 100mA CIN = 2.2uF, COUT = 100uF 10 0 -10
5 0
Input Voltage Deviation (V)
Load Current(A)
2.5 1.5
Time (250us/Div)
Time (100us/Div)
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RT9194
Application Information
Capacitors Selection Careful selection of the external capacitors for RT9194 is highly recommended in order to remain high stability and performance. Regarding the supply voltage capacitor, connecting a capacitor which is 1F between VCC and ground is a must. The capacitor improves the supply voltage stability to provide chip normally operating. Regarding the input capacitor, connecting a capacitor which 100F between VIN and ground is recommended to increase stability. With large value of capacitance could result in better performance for both PSRR and line transient response. When driving external pass element, connecting a capacitor 100F between V OUT and ground is recommended for stability. With larger capacitance can reduce noise and improve load transient response and PSRR. Output Voltage Setting The RT9194 develop a 0.8V reference voltage; especially suit for low voltage application. As shown in application circuit, the output voltage could easy set the output voltage by R1 & R2 divider resistor. Power Good Function The RT9194 has the power good function with delay. The power good output is an open drain output. Connect a 100k pull up resistor to VOUT to obtain an output voltage. When the output voltage arrive 90% of normal value the power good will output voltage with 3ms delay time. When the output voltage falling arrive 75% of normal value the power good will turn off with less than 1ms delay time. But, there are two exceptions. One is the enable pull low the power good will turn off quickly. The second is the VCC falling arrive POR value (4V typ.) the power good also will turn off quickly. Chip Enable Operation Pull the EN pin low to drive the device into shutdown mode. During shutdown mode, the standby current drops to 5A(MAX). The external capacitor and load current determine the output voltage decay rate. Drive the EN pin high to turn on the device again. Under Voltage Protection RT9194 equips the VOUT under-voltage (UV) protection function. The UV protection circuits will start monitoring the power status after the PGOOD pin goes high. If the output voltage drops to below 75% of its setting value, the PGOOD and DRI pins will be pulled low and latch RT9194. The UV latch status will be released only when VCC or Enable pin goes low and returns high again, which will also cause RT9194 to re-activate. MOSFET Selection The RT9194 are designed to driver external N-Channel MOSFET pass element. MOSFET selection criteria include threshold voltage V GS (V TH ), maximum continuous drain current ID, on-resistance R DS(ON) ,maximum drain-to-source voltage VDS and package thermal resistance (JA). The most critical specification is the MOSFET RDS(ON). Calculate the required RDS(ON) from the following formula: V - VOUT NMOSFET RDS(ON) = IN ILOAD For example, the MOSFET operate up to 2A when the input voltage is 1.5V and set the output voltage is 1.2V, R ON = (1.5V-1.2V) / 2A = 150m, the MOSFET's RON have to select lower than 150m. A Philip PHD3055E MOSFET with an RDS(ON) of 120m(typ.) is a close match. And carry on consider the thermal resistance from junction to ambient (JA) of the MOSFET's package. The power dissipation calculate by : PD = (VIN - VOUT) x ILOAD The thermal resistance from junction to ambient (JA) calculate by : (T - T ) (JA) = J A PD In this example, PD = (1.5V - 1.2V) x 2A = 0.6W. The PHD3055E's (JA) is 75C/W for its D-PAK package, which translates to a 45C temperature rise above ambient. The package provides exposed backsides that directly transfer heat to the PCB board.
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RT9194
PNP Transistor Selection The RT9194 could driver the PNP transistor to sink output current. PNP transistor selection criteria include DC current gain hFE, threshold voltage VEB, collector-emitter voltage VCE, maximum continues collector current IC, package thermal resistance (JA). For example, the PNP transistor operates sink current up to 0.5A when the input voltage is 1.5V and set the output voltage is 1.2V. As show in Figure 3. A KSB772 PNP transistor, the VCE = 1.2V, VBE = -1V, IC = 0.5A, IB = 0.5/160 ] 3.125mA, when the DRI pin voltage is 0.2V could sink 6.8mA(MAX) is a close match.
Sink Current vs. DRI Voltage
VIN
25
PGOOD
VCC
VCC Ccc GND
DRI PGOOD RT9194 FB Q2 RPGOOD
Q1 VOUT R1 COUT
Sink Current (mA)
CIN
20
15
Chip Enable
EN
10
5
R2
TA = 25C
0 0 0.5 1 1.5 2 2.5 3
Figure 3
DRI Voltage (V)
Figure 4 Layout Considerations There are three critical layout considerations. One is the divider resistors should be located to RT9194 as possible to avoid inducing any noise. The second is capacitors place. The CIN and COUT have to put at near the NMOS for improve performance. The third is the copper area for pass element. We have to consider when the pass element operating under high power situation that could rise the junction temperature. In addition to the package thermal resistance limit, we could add the copper area to improve the power dissipation. As show in Figure 5 and Figure 6.
VIN
VIN
PGOOD CIN
+
VCC
VCC Ccc GND
DRI PGOOD RT9194 FB RPGOOD
Q1 VOUT
GND
Chip Enable
EN
VCC
R1 COUT
+
PGOOD VOUT EN FB
+
R2
GND
Figure 5
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Figure 6
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RT9194
Outline Dimension
H D L C B
b A A1 e
Symbol A A1 B b C D e H L
Dimensions In Millimeters Min 0.889 0.000 1.397 0.250 2.591 2.692 0.838 0.080 0.300 Max 1.295 0.152 1.803 0.560 2.997 3.099 1.041 0.254 0.610
Dimensions In Inches Min 0.031 0.000 0.055 0.010 0.102 0.106 0.033 0.003 0.012 Max 0.051 0.006 0.071 0.022 0.118 0.122 0.041 0.010 0.024
SOT-23-6 Surface Mount Package
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) 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com
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