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Preliminary
RT9183
Ultra Low Dropout 1.5A Linear Regulator
General Description
The RT9183 series are high performance linear voltage regulators that provide ultra low-dropout voltage, high output current with low ground current. It operates from an input of 2.3V to 5.5V and provides output current up to 1.5A thus is suitable to drive digital circuits requiring low voltage at high currents. The RT9183 has superior regulation over variations in line and load. Also it provides fast respond to step changes in load. Other features include over-current and overtemperature protection. The adjustable version has enable pin to reduce power consumption in shutdown mode. The devices are available in fixed output voltages of 1.8V, 2.5V, 3.3V and as an adjustable device with a 0.8V reference voltage. The RT9183 regulators are available in 3-lead SOT-223 and TO-263 packages (fixed output only for the 3-lead option). Also available are 5-lead TO-263 and fused SOP-8 packages with two external resistors to set the output voltage ranges from 0.8V to 4.5V.
Features
330mV Dropout @ 1.5A 380A Low Ground Pin Current Excellent Line and Load Regulation 0.1mA Quiescent Current in Shutdown Mode Guaranteed 1.5A Output Current Fixed Output Voltages: 1.8V, 2.5V, 3.3V Adjustable Output Voltage from 0.8V to 4.5V Over-Temperature/Over-Current Protection
Applications
Battery-Powered Equipment Mother Board/Graphic Card Peripheral Cards PCMCIA Card
Pin Configurations
(TOP VIEW)
Ordering Information
RT9183
Package Type G : SOT-223 S : SOP-8 M : TO-263 M5 : TO-263-5 Operating Temperature Range C : Commercial Standard Output Voltage Defauit : Adjustable 18 : 1.8V 25 : 2.5V 33 : 3.3V H : Chip Enable High L : Chip Enable Low
1
2
3
EN VIN VOUT ADJ
2 3 4
8 7 6 5
GND GND GND GND
9,1 *1' 9287 7$%
SOP-8
SOT-223
3 2 1 9287 *1' 7$% 9,1
TO-263
5 4 3 2 1
$'9287 *1' 7$% 9,1 (1
TO-263-5
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RT9183
Typical Application Circuit
Preliminary
(SOT-223 & TO-263) RT9183 VIN = 3.3V CIN 10uF VIN GND VOUT COUT 10 uF VOUT 2.5V, 1.5A
Figure 1. 3.3V to 2.5V Regulator
(SOP-8 & TO-263-5) VIN Enable RT9183 VIN VOUT R1 C3 0.1 uF C1 1 10uF EN GND ADJ R2 C2 10uF VOUT
VOUT = 0.8x (1+
R1 )Volts R2
Note: The value of R2 should be less than 80k to maintain regulation.
Figure 2. Adjustable Operation
(SOP-8 & TO-263-5) VIN Enable C3 0.1uF C1 10uF
VIN EN
RT9183 VOUT GND ADJ
C2 10 uF
VOUT
Figure 3. Fixed Operation with SOP-8 and TO-263-5 packages
Functional Pin Description
Pin Name EN VIN GND VOUT ADJ Chip Enable Control Input. Note that the device will be in the unstable state if the pin is not connected. Supply Input Common Ground Regulator Output The output voltage is set by the internal feedback resistors when this pin grounded. If external feedback resistors are applied, the output voltage will be: VOUT = 0.8 x (1 + R1 ) Volts
R2
Pin Function
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Preliminary Function Block Diagram
VIN Current Limit Sensor + 0.8V Reference
Error Amplifier
RT9183
-
+ VOUT
EN
Shutdown Logic
Thermal Shutdown ADJ
Output Mode Comparator
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100mV GND
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RT9183
Absolute Maximum Ratings
Preliminary
(Note 1)
Supply Input Voltage -------------------------------------------------------------------------------------------------- 6V Package Thermal Resistance SOT-223, JC ------------------------------------------------------------------------------------------------------------ 15 C/W SOP-8, JC -------------------------------------------------------------------------------------------------------------- 15.7 C/W TO-263, JC ------------------------------------------------------------------------------------------------------------- 8C/W Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260C Junction Temperature ------------------------------------------------------------------------------------------------- 150C Storage Temperature Range ---------------------------------------------------------------------------------------- -65C to 150C ESD Susceptibility (Note 2) HBM ---------------------------------------------------------------------------------------------------------------------- 2kV MM ------------------------------------------------------------------------------------------------------------------------ 200V
Recommended Operating Conditions
(Note 3)
Supply Input Voltage ------------------------------------------------------------------------------------------------- 2.3V to 5.5V Junction Temperature Range --------------------------------------------------------------------------------------- -40C to 125C
Electrical Characteristics
(VIN = VOUT + 0.7V, CIN =COUT = 10F (Ceramic), TA = 25C unless otherwise specified)
Parameter Output Voltage Accuracy (Fixed Output Voltage) Output Voltage Range (Adjustable) Quiescent Current (Note 6) Standby Current (Note 7) Current Limit Dropout Voltage (Note 4)
Symbol VOUT VOUT_Adj IQ ISTBY ILIM
Test Conditions IOUT = 10mA
Min -2 0.8
Typ 0 -380 0.1 3.2 110 220 330 0.035
Max +2 4.5 500 1 3.9 300 400 500 0.18
Units % V A A A mV
IOUT = 0mA, Enable VIN = 5.5V, Shutdown IOUT = 0.5A
--2 -----
VDROP
IOUT = 1.0A IOUT = 1.5A VOUT + 0.7V < VIN < 5.5V IOUT = 10mA 1mA < IOUT < 1.5A
Line Regulation Load Regulation (Note 5) (Fixed Output Voltage) Thermal Shutdown Temperature Thermal Shutdown Hysteresis EN Threshold Logic-Low Voltage Logic-High Voltage
VLINE VLOAD TSD TSD VIL VIH IEN
%/V
----
22 170 30 --0.1
45 --0.6 -1
mV C C V A
VIN = 5.5V VIN = 5.5V VIN = 5.5V, Enable
-1.8 --
Enable Pin Current
To be continued
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Preliminary
Parameter ADJ Reference Voltage Tolerance Adjust Pin Current Adjust Pin Threshold VREF IADJ VTH(ADJ) VADJ = VREF 0.784 -0.05 0.8 10 0.1 Symbol Test Conditions Min Typ
RT9183
Max 0.816 100 0.2 Units V nA V
Note 1. Stresses beyond those listed under "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 for extended periods may affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution recommended. The human body model is a 100pF capacitor discharged through a 1.5K resistor into each pin. Note 3. The device is not guaranteed to function outside its operating conditions. Note 4. Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 0.7V differential. Note 5. Regulation is measured at constant junction temperature by using a 20mS current pulse. Devices are tested for load regulation in the load range from 10mA to 1.5A. Note 6. 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 7. Standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown signal (VEN >1.8V ). It is measured with VIN = 5.5V.
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RT9183
Preliminary
Typical Operating Characteristics
Output Voltage vs. Temperature
1.9
Output Voltage vs. Temperature
2.6
VIN = 5V, RL = CIN = COUT = 10uF (Ceramic,Y5V)
1.85
VIN = 5V, RL = CIN = COUT = 10uF (Ceramic,Y5V)
2.55
1.8
2.5
1.75
2.45
RT9183H-18CS
1.7 -50 -25 0 25 50 75 100 125
RT9183-25CG
2.4 -50 -25 0 25 50 75 100 125
Temperature (C)
Temperature (C)
Quiescent Current vs. Temperature
400
Quiescent Current vs. Temperature
400
380
380
360
360
340
340
320
VIN = 5V, RL = CIN = COUT = 10uF (Ceramic,Y5V)
-50 -25 0 25 50
320
VIN = 5V, RL = CIN = COUT = 10uF (Ceramic,Y5V)
-50 -25 0 25 50
300
RT9183H-18CS
300
75 100 125
RT9183-25CG
75 100 125
Temperature (C)
Temperature (C)
Current Limit vs. Temperature
4
Current Limit vs. Temperature
4
VIN = 5V, CIN = COUT = 10uF(Ceramic,Y5V)
3.8
VIN = 5V, CIN = COUT = 10uF(Ceramic,Y5V)
3.8
3.6
3.6
3.4
3.4
3.2
3.2
3 -50 -25 0 25 50
RT9183-25CG
75 100 125
RT9183L-33CM5
3 -50 -25 0 25 50 75 100 125
Temperature (C)
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Temperature (C)
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Preliminary
RT9183
Dropout Voltage
500
Dropout Voltage
500
TJ = 125C
400
TJ = 125C
400
300
300
200
TJ = +25C TJ = -40C RT9183-25CG
TJ = +25C
200
TJ = -40C
100
100
0 0 0.3 0.6 0.9 1.2 1.5
0 0 0.3 0.6 0.9
RT9183L-33CM5
1.2 1.5
Load Current (A)
Load Current (A)
Load Transient Response
COUT = 47uF/Low ESR, ILOAD = 1mA to 750mA
Load Transient Response
COUT = 47uF/Low ESR, ILOAD = 1mA to 1.5A
Load Current (A)
0.5 0
Load Current (A) Output Voltage Deviation(mV)
1
2 1 0 50
Output Voltage Deviation(mV)
20 0 -20 RT9183H-18CS
0 -50 RT9183H-18CS
Time (100us/Div)
Time (100us/Div)
Line Transient Response
Input Voltage Deviation(V)
COUT = 47uF/Low ESR, ILOAD = 100mA 5 4
2
Copper Area vs. Power Dispation
350
RT9183H-18CS ,TJ= 125C
300 250
Output Voltage Deviation(mV)
10 0 -10
200 150 100
RT9183H-18CS
50
TA= 65C TA= 50C
1 1.5 2
TA= 25C
2.5 3
Time (100us/Div) DS9183-02 December 2003
Power Dissipation (W)
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RT9183
Preliminary
EN Pin Shutdown Threshold vs. Temperature
1.1
EN Pin Shutdown Response
CIN = COUT = 10uF (Ceramic,Y5V)
EN Voltage (V)
ILOAD = 100mA, VIN = 5V, TA =25C 5 0
1
VOUT Off to On
0.9
Output Voltage (V)
VOUT On to Off
0.8
2 1 0 RT9183H-18CS
RT9183L-33CM5
0.7 -50 -25 0 25 50 75 100 125
Temperature (C)
Time (500us/Div)
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Preliminary Application Information
Like any low-dropout regulator, the RT9183 series requires input and output decoupling capacitors. These capacitors must be correctly selected for good performance (see Capacitor Characteristics Section). Please note that linear regulators with a low dropout voltage have high internal loop gains which require care in guarding against oscillation caused by insufficient decoupling capacitance. INPUT CAPACITOR An input capacitance of 10F is required between the device input pin and ground directly (the amount of the capacitance may be increased without limit). The input capacitor MUST be located less than 1 cm from the device to assure input stability (see PCB Layout Section). A lower ESR capacitor allows the use of less capacitance, while higher ESR type (like aluminum electrolytic) require more capacitance. Capacitor types (aluminum, ceramic and tantalum) can be mixed in parallel, but the total equivalent input capacitance/ ESR must be defined as above to stable operation. There are no requirements for the ESR on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance will be10F over the entire operating temperature range. OUTPUT CAPACITOR The RT9183 is designed specifically to work with very small ceramic output capacitors. The recommended minimum capacitance (temperature characteristics X7R or X5R) are 10F to 47F range with 10m to 25m range ceramic capacitors between each LDO output and GND for transient stability, but it may be increased without limit. Higher capacitance values help to improve transient. The output capacitor's ESR is critical because it forms a zero to provide phase lead which is required for loop stability. (When using the Y5V dielectric, the minimum value of the input/output capacitance that can be used for stable over full operating temperature range is 3.3F.) NO LOAD STABILITY
RT9183
The device will remain stable and in regulation with no external load. This is specially important in CMOS RAM keep-alive applications. INPUT-OUTPUT (DROPOUT) VOLTAGE 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 PMOS, its dropout voltage is a function of drain-to-source on-resistance, RDS(ON), multiplied by the load current: VDROPOUT = VIN - VOUT = RDS(ON) x IOUT CURRENT LIMIT The RT9183 monitors and controls the PMOS' gate voltage, minimum limiting the output current to 2A . The output can be shorted to ground for an indefinite period of time without damaging the part. SHORT-CIRCUIT PROTECTION The device is short circuit protected and in the event of a peak over-current condition, the short-circuit control loop will rapidly drive the output PMOS pass element off. Once the power pass element shuts down, the control loop will rapidly cycle the output on and off until the average power dissipation causes the thermal shutdown circuit to respond to servo the on/off cycling to a lower frequency. Please refer to the section on thermal information for power dissipation calculations. CAPACITOR CHARACTERISTICS It is important to note that capacitance tolerance and variation with temperature must be taken into consideration when selecting a capacitor so that the minimum required amount of capacitance is provided over the full operating temperature range. In general, a good tantalum capacitor will show very little capacitance variation with temperature, but a ceramic may not be as good (depending on dielectric type). Aluminum electrolytics also typically have large temperature variation of capacitance value.
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RT9183
Preliminary
The increasing ESR at lower temperatures can cause oscillations when marginal quality capacitors are used (if the ESR of the capacitor is near the upper limit of the stability range at room temperature). Aluminum: This capacitor type offers the most capacitance for the money. The disadvantages are that they are larger in physical size, not widely available in surface mount, and have poor AC performance (especially at higher frequencies) due to higher ESR and ESL. Compared by size, the ESR of an aluminum electrolytic is higher than either Tantalum or ceramic, and it also varies greatly with temperature. A typical aluminum electrolytic can exhibit an ESR increase of as much as 50X when going from 25C down to -40C. It should also be noted that many aluminum electrolytics only specify impedance at a frequency of 120Hz, which indicates they have poor high frequency performance. Only aluminum electrolytics that have an impedance specified at a higher frequency (between 20kHz and 100kHz) should be used for the device. Derating must be applied to the manufacturer's ESR specification, since it is typically only valid at room temperature. Any applications using aluminum electrolytics should be thoroughly tested at the lowest ambient operating temperature where ESR is maximum. THERMAL CONSIDERATIONS The RT9183 series can deliver a current of up to 1.5A over the full operating junction temperature range. However, the maximum output current must be derated at higher ambient temperature to ensure the junction temperature does not exceed 125C. With all possible conditions, the junction temperature must be within the range specified under operating conditions. Power dissipation can be calculated based on the output current and the voltage drop across regulator. PD = (VIN - VOUT) IOUT + VIN IGND
Equally important to consider is a capacitor's ESR change with temperature: this is not an issue with ceramics, as their ESR is extremely low. However, it is very important in tantalum and aluminum electrolytic capacitors. Both show increasing ESR at colder temperatures, but the increase in aluminum electrolytic capacitors is so severe they may not be feasible for some applications. Ceramic: For values of capacitance in the 10F to 100F range, ceramics are usually larger and more costly than tantalums but give superior AC performance for by-passing high frequency noise because of very low ESR (typically less than 10m). However, some dielectric types do not have good capacitance characteristics as a function of voltage and temperature. Z5U and Y5V dielectric ceramics have capacitance that drops severely with applied voltage. A typical Z5U or Y5V capacitor can lose 60% of its rated capacitance with half of the rated voltage applied to it. The Z5U and Y5V also exhibit a severe temperature effect, losing more than 50% of nominal capacitance at high and low limits of the temperature range. X7R and X5R dielectric ceramic capacitors are strongly recommended if ceramics are used, as they typically maintain a capacitance range within 20% of nominal over full operating ratings of temperature and voltage. Of course, they are typically larger and more costly than Z5U/ Y5U types for a given voltage and capacitance. Tantalum: Solid tantalum capacitors are recommended for use on the output because their typical ESR is very close to the ideal value required for loop compensation. They also work well as input capacitors if selected to meet the ESR requirements previously listed. Tantalums also have good temperature stability: a good quality tantalum will typically show a capacitance value that varies less than 10~15% across the full temperature range of 125C to -40C. ESR will vary only about 2X going from the high to low temperature limits.
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Preliminary
The final operating junction temperature for any set of conditions can be estimated by the following thermal equation: PD (MAX) = ( TJ (MAX) - TA ) / JA Where TJ (MAX) is the maximum junction temperature of the die (125C) and T A is the maximum ambient temperature. The junction to ambient thermal resistance (JA) for SOP-8 package at recommended minimum footprint is 42C/W, 40C/W for SOT-223 package and 25C/W for TO-263 package (JA is layout dependent). Visit our website in which "Recommended Footprints for Soldering Surface Mount Packages" for detail. 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 diagram below:
+ EN GND
RT9183
ADJ
VOUT
+
GND
SOP-8 Board Layout ADJUSTABLE OPERATION The adjustable version of the RT9183 has an output voltage range of 0.8V to 4.5V. The output voltage is set by the ratio of two external resistors as shown in Figure 2. The value of R2 should be less than 80k to maintain regulation. In critical applications, small voltage drop is caused by the resistance (RT) of PC traces between the ground pin of the device and the return pin of R2 (See Figure 4 shown on next page). Note that the voltage drop across the external PC trace will add to the output voltage of the device. Optimum regulation will be obtained at the point where the return pin of R2 is connected to the ground pin of the device directly.
(SOP-8 & TO-263-5) RT9183 VIN Enable C3 0.1uF C1 10uF VIN VOUT R1 EN GND ADJ RT R2 C2 10uF VOUT
Figure 4. Return Pin of External Resistor Connection Referring to Figure 3 the fixed voltage versions for both SOP-8 and TO-263-5 packages, the ADJ pin is the input to the error amplifier and MUST be tied the ground pin of the device directly otherwise it will be in the unstable state if the pin voltage more than 0.1V with respect to the ground pin itself.
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VIN GND
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RT9183
Outline Dimension
Preliminary
D D1
H
C
B
L e e
A b
A1
Symbol A A1 b B C D D1 e H L
Dimensions In Millimeters Min -0.020 0.610 3.302 6.706 6.299 2.896 2.261 0.229 0.914 Max 1.803 0.100 0.787 3.708 7.290 6.706 3.150 2.362 0.330 --
Dimensions In Inches Min -0.0008 0.024 0.130 0.264 0.248 0.114 0.089 0.009 0.036 Max 0.071 0.0047 0.031 0.146 0.287 0.264 0.124 0.093 0.013 --
3-Lead SOT-223 Plastic Surface Mount
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Preliminary
RT9183
H M
A
J
B
F
C I D
Symbol A B C D F H I J M
Dimensions In Min 4.801 3.810 1.346 0.330 1.194 0.178 0.102 5.791 0.406 Max 5.004 3.988 1.753 0.508 1.346 0.254 0.254 6.198 1.270
Dimensions In Inches Min 0.189 0.150 0.053 0.013 0.047 0.007 0.004 0.228 0.016 Max 0.197 0.157 0.069 0.020 0.053 0.010 0.010 0.244 0.050
8-Lead SOP Plastic Package
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RT9183
D B
Preliminary
C
U
V E L1
b1 L2 e b b2
A
Symbol A B b b1 b2 C D E e L1 L2 U V
Dimensions In Millimeters Min 4.064 1.143 0.660 1.143 0.305 1.143 9.652 8.128 2.286 14.605 2.286 Max 4.826 1.676 0.914 1.397 0.584 1.397 10.668 9.652 2.794 15.875 2.794
Dimensions In Inches Min 0.160 0.045 0.026 0.045 0.012 0.045 0.380 0.320 0.090 0.575 0.090 Max 0.190 0.066 0.036 0.055 0.023 0.055 0.420 0.380 0.110 0.625 0.110
6.223 Ref. 7.620 Ref.
0.245 Ref. 0.300 Ref.
3-Lead TO- 263 Surface Mount
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Preliminary
RT9183
D B
C
U
V E L1
L2 e b b2
A
Symbol A B b b2 C D E e L1 L2 U V
Dimensions In Millimeters Min 4.064 1.143 0.660 0.305 1.143 9.652 8.128 1.524 14.605 2.286 Max 4.826 1.676 0.914 0.584 1.397 10.668 9.652 1.829 15.875 2.794
Dimensions In Inches Min 0.160 0.045 0.026 0.012 0.045 0.380 0.320 0.060 0.575 0.090 Max 0.190 0.066 0.036 0.023 0.055 0.420 0.380 0.072 0.625 0.110
6.223 Ref. 7.620 Ref.
0.245 Ref. 0.300 Ref.
5-Lead TO-263 Plastic Surface Mount Package
RICHTEK TECHNOLOGY CORP.
Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611
RICHTEK TECHNOLOGY CORP.
Taipei Office (Marketing) 8F-1, 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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