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Si91872
Vishay Siliconix
300-mA Low-Noise LDO Regulator With Error Flag and Discharge Option
FEATURES
D D D D D D D D D D D D D D Ultra Low Dropout--300 mV at 300-mA Load Low Noise--75 mVRMS (10-Hz to 100-kHz) Out-of-Regulation Error Flag (power good) Shutdown Control 130-mA Ground Current at 300-mA Load Fast Start-Up (50 mS) 1.5% Guaranteed Output Voltage Accuracy 400-mA Peak Output Current Capability Uses Low ESR Ceramic Capacitors Fast Line and Load Transient Response (v 30 ms) 1-mA Maximum Shutdown Current Output Current Limit Reverse Battery Protection Built-in Short Circuit and Thermal Protection D Output--Auto-Discharge In Shutdown Mode D Fixed 1.2, 1.8, 2.5, 2.6, 2.8, 3.0, 3.3, 5.0-V Output Voltage Options D MLP33-5 PowerPAKr Package
Available
APPLICATIONS
D Cellular Phones, Wireless Handsets D Noise-Sensitive Electronic Systems, Laptop and Palmtop Computers D PDAs D Pagers D Digital Cameras D MP3 Player D Wireless Modem
DESCRIPTION
The Si91872 is a 300-mA CMOS LDO (low dropout) voltage regulator. It is the perfect choice for low voltage, low power applications. An ultra low ground current and ultra fast turn-on make this part attractive for battery operated power systems. The Si91872 also offers ultra low dropout voltage to prolong battery life in portable electronics. Systems requiring a quiet voltage source will benefit from the Si91872's low output noise. The Si91872 is designed to maintain regulation while delivering 400-mA peak current, making it ideal for systems that have a high surge current upon turn-on. For better transient response and regulation, an active pull-down circuit is built into the Si91872 to clamp the output voltage when it rises beyond normal regulation. The Si91872 automatically discharges the output voltage by connecting the output to ground through a 100-W n-channel MOSFET when the device is put in shutdown mode. The Si91872 features reverse battery protection to limit reverse current flow to approximately 1-mA in the event reversed battery is applied at the input, thus preventing damage to the IC. The Si91872 is available in both the standard and lead (Pb)-free 5-pin MLP33 PowerPAK packages and is specified to operate over the industrial temperature range of -40_C to 85_.
TYPICAL APPLICATION CIRCUIT
Si91872
VIN 2.2 mF SD SD 51 kW VIN VOUT VOUT 2.2 mF
GND
ERROR
ERROR
MLP33-5
Document Number: 72013 S-51147--Rev. F, 20-Jun-05
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Si91872
Vishay Siliconix
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings Input Voltage, VIN to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -6.0 to 6.5 V VERROR, VSD (See Detailed Description) . . . . . . . . . . . . . . . . . . -0.3 V to VIN Output Current, IOUT . . . . . . . . . . . . . . . . . . . . . . . . . . Short Circuit Protected Output Voltage, VOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to VIN + 0.3 V Package Power Dissipation, (Pd)b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 W Thermal Resistance (qJA)a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55_C/W R(qJA)a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8_C/W Maximum Junction Temperature, TJ(max) . . . . . . . . . . . . . . . . . . . . . . . 150_C Storage Temperature, TSTG . . . . . . . . . . . . . . . . . . . . . . . . . . -65_C to 150_C Notes a. Device mounted with all leads soldered or welded to PC board. b. Derate 20 mW/_C above TA = 25_C
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.
RECOMMENDED OPERATING RANGE
Input Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 V to 6 V Input Voltage, VSD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to VIN Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 300 mA CIN, COUTa (Ceramic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 mF Operating Ambient Temperature, TA . . . . . . . . . . . . . . . . . . . . -40_C to 85_C Operating Junction Temperature, TJ . . . . . . . . . . . . . . . . . . . -40_C to 125_C Notes a. Maximum ESR of COUT: 0.2 W.
SPECIFICATIONS
Test Conditions Unless Specified Parameter
Input Voltage Range
Limits
-40 to 85_C
Symbol
VIN
TA = 25_C, VIN = VOUT(nom) + 1 V, IOUT = 1 mA, CIN = 2 mF, COUT = 2.0 mF, VSD = 1.5 V
Tempa
Full
Minb
2 -2.0 -3.0 -2.5 -3.5 -0.06 0 0
Typc
Maxb
6
Unit
V
VOUT w 1 8 V 1.8 Output Voltage Accuracy 1 mA v IOUT v 300 mA VOUT = 1.2 V, 1.5 V 12V 15 Line Regulation (VOUT v 3 V) Line Regulation (3.0 V < VOUT v3.6 V) Line Regulation (5-V Version) DVOUT DVIN 100 From VIN = VOUT(nom) + 1 V to VOUT(nom) + 2 V VOUT(nom) ( ) From VIN = 5.5 V to 6 V IOUT = 1 mA
d, Dropout V lt D t Voltaged g (VOUT(nom) w 2.6 V)
Room Full Room Full Full Full Full Room Room Full Room Full Room Full Room Full Room Full Room Full Room Full Room Full Full Room
1 1 1 1
2.0 3.0 2.5 3.5 0.18 0.3 0.4 %/V %
1 45 50 300 65 400 100 130 110 150 400 75 80 90 350 415 100 120 520 570 150 180 200 330 170 200 225 275 mA mV(rms) mA mV
IOUT = 50 mA IOUT = 300 mA IOUT = 50 mA IOUT = 300 mA IOUT = 0 mA IOUT = 300 mA IGND IOUT = 0 mA IOUT = 300 mA IO(peak) eN VOUT w 0.95 x VOUT(nom). tPW = 2 ms VOUT = 2.6 V, BW = 10 Hz to 100 kHz, 0 mA t IOUT t 150 mA
VIN - VOUT Dropout Voltaged, g (VOUT(nom) t 2.6 V, VIN w 2 V) ( )
Ground Pin Currente, g (VOUT(nom) v 3 V) ( )
Ground Pin Currente, g (VOUT(nom) u 3 V) ( ) Peak Output current Output Noise Voltage
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Document Number: 72013 S-51147--Rev. F, 20-Jun-05
Si91872
Vishay Siliconix
SPECIFICATIONS
Test Conditions Unless Specified Parameter Symbol
TA = 25_C, VIN = VOUT(nom) + 1 V, IOUT = 1 mA, CIN = 2 mF, COUT = 2.0 mF, VSD = 1.5 V
Limits
-40 to 85_C
Tempa
Room Room Room Room Room Room Room
Minb
Typc
60 40 30 20 25 150 20 1 700
Maxb
Unit
f = 1 kHz Ripple Rejection pp j DVOUT/DVIN DVO(line) DVO(load) TJ(S/D) THYST IR ISC VIN = -6.0 V VOUT = 0 V IOUT = 300 mA f = 10 kHz f = 100 kHz Dynamic Line Regulation Dynamic Load Regulation Thermal Shutdown Junction Temperature Thermal Hysteresis Reverse current Short Circuit Current VIN : VOUT(nom) + 1 V to VOUT(nom) + 2 V tr/tf = 2 ms, IOUT = 300 mA IOUT : 1 mA to 300 mA, tr/tf = 2 ms
dB
mV
_C C mA mA
Room Room
Shutdown
Shutdown Supply Current SD Pin Input Voltage Auto Discharge Resistance SD Pin Input Currentf SD Hysteresis VOUT Turn-On Time ICC(off) VSD R_DIS IIN(SD) VHYST(SD) tON VSD (See Figure 1), ILOAD = 100 mA VSD = 0 V High = Regulator ON (Rising) Low = Regulator OFF (Falling) Si91872 Only VSD = 1.5 V, VIN = 6 V Room Full Full Room Room Full Room 100 0.7 150 50 1.5 0.1 1 VIN 0.4 mA V W mA mV ms
ERROR Output
ERROR High Leakage ERROR Low Voltage ERROR Voltage Threshold ERROR Voltage Threshold Hysteresis IOFF VOL VERROR VHYST(ERROR) ERROR v VIN. VOUT in Regulation ISINK = 0.5 mA VOUT Below VOUT(nom)g, VIN w 2 V VOUT Falling, IOUT = 1 mA, VOUT(nom) w 2 V VOUT(nom)g t 2 V, VIN u 2 V Full Full Full Full Room -2 -4 -4 1.5 1 0.4 -6 % mA V
Notes a. Room = 25_C, Full = -40 to 85_C. b. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum. c. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing. d. Dropout voltage is defined as the input to output differential voltage at which the output voltage drops 2% below the output voltage measured with a 1-V differential, provided that VIN does not not drop below 2.0 V. e. Ground current is specified for normal operation as well as "drop-out" operation. f. The device's shutdown pin includes a typical 2-MW internal pull-down resistor connected to ground. g. VOUT(nom) is VOUT when measured with a 1-V differential to VIN.
TIMING WAVEFORMS
VIN VSD tr v 1 mS
0V
tON VNOM 0.95 VNOM
VOUT
FIGURE 1. Timing Diagram for Power-Up
Document Number: 72013 S-51147--Rev. F, 20-Jun-05
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Si91872
Vishay Siliconix
PIN CONFIGURATION: MLP33-5
MLP33-5 PowerPAK
SD ERROR VIN VOUT 2
1
GND GND 5 5 GND GND
1 2 3 4
3 4
Top View
Bottom View
PIN DESCRIPTION
Pin Number
1 2 3 4 5
Name
SD ERROR VIN VOUT GND
Function
By applying less than 0.4 V to this pin, the device will be turned off. Connect this pin to VIN if unused The open drain output is an error flag output which goes low when VOUT drops 4% below its nominal voltage. Input supply pin. Bypass this pin with a 1-mF ceramic or tantalum capacitor to ground Output voltage. Connect COUT between this pin and ground. Ground pin. For better thermal capability, directly connected to large ground plane
ORDERING INFORMATION
Standard Part Number
Si91872DMP-12-T1 Si91872DMP-18-T1 Si91872DMP-25-T1 Si91872DMP-26-T1 Si91872DMP-28-T1 Si91872DMP-30-T1 Si91872DMP-33-T1 SI91872DMP-50-T1
Lead (Pb)-Free Part Number
Si91872DMP-12-E3 Si91872DMP-18-E3 Si91872DMP-25-E3 Si91872DMP-26-E3 Si91872DMP-28-E3 Si91872DMP-30-E3 Si91872DMP-33-E3 Si91872DMP-50-E3
Marking
7212 7218 7225 7226 7228 7230 7233 7250
Voltage
1.2 1.8 2.5 2.6 2.8 3.0 3.3 5.0
Temp. Range
Pkg.
-40 to 85_C 40
MLP33-5 MLP33 5
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Document Number: 72013 S-51147--Rev. F, 20-Jun-05
Si91872
Vishay Siliconix
TYPICAL CHARACTERISTICS (INTERNALLY REGULATED, 25_C UNLESS NOTED)
0.30 0.15 0.00 -0.15 -0.30 -0.45 -0.60 -0.75 0 50 100 150 200 250 300 Load Current (mA) V OUT (%)
Normalized Output Voltage vs. Load Current
VIN = VOUT(nom) + 1 V
0.4 0.2
Normalized VOUT vs. Temperature
VIN = VOUT(nom) + 1 V IOUT = 0 mA
Output Voltage (%)
-0.0 -0.2 -0.4 -0.6 -0.8 -1.0 -40
IOUT = 75 mA IOUT = 150 mA IOUT = 300 mA
-15
10
35
60
85
Ambient Temperature (_C)
150
GND Current vs. Load Current
VOUT = 3.0 V VIN = 4.0 V 85_C
300 250
No Load GND Pin Current vs. Input Voltage
125 25_C I GND ( mA) I GND ( mA) 100 200 150 100 75 50 50 0 50 100 150 200 250 300 Load Current (mA) 0 2 3 4 5 6 7 Input Voltage (V)
-40_C
85_C 25_C -40_C
0
Power Supply Rejection
CIN = 1 mF COUT = 1 mF ILOAD = 150 mA VOUT = 3.0 V I SC (mA)
750 725 700
Output Short Circuit Current vs. Temperature
VOUT = 2.6 V
-20
Gain (dB)
-40
675 650
-60 625 -80 10 600 -40
100
1000
10000
100000
1000000
-15
10
35
60
85
Frequency (Hz) Document Number: 72013 S-51147--Rev. F, 20-Jun-05
AmbientTemperature (_C)
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Si91872
Vishay Siliconix
TYPICAL CHARACTERISTICS (INTERNALLY REGULATED, 25_C UNLESS NOTED)
350 300 250 V DROP (mV) 200 150 100 50 0 0 60 120 180 240 300 ILOAD (mA) V OUT (V)
Dropout Voltage vs. Load Current
VOUT = 3.0 V
3.0 2.5 2.0 1.5 1.0 0.5 0.0 0
VIN - VOUT Transfer Characteristic
VOUT = 3.0 V
1
2
3 VIN (V)
4
5
6
350 300 250 V DROP (mV) 200 150 100 50 0 -50
Dropout Voltage vs. Temperature
VOUT = 3.0 V IOUT = 300 mA Dropout Voltage (mV)
400 350 300 250 200 150 100 50 IOUT = 10 mA IOUT = 0 mA 0 1.0
Dropout Voltage vs. VOUT
IOUT = 300 mA
IOUT = 150 mA
IOUT = 75 mA
IOUT = 75 mA
IOUT = 150 mA
IOUT = 10 mA 1.5 2.0 2.5 3.0 VOUT 3.5 4.0 4.5 5.0
-25
0
25
50
75
100
125
150
Junction Temperature (_C)
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Document Number: 72013 S-51147--Rev. F, 20-Jun-05
Si91872
Vishay Siliconix
TYPICAL WAVEFORMS
Load Transient Response-1
Load Transient Response-2
VOUT 10 mV/div VOUT 10 mV/div
ILOAD 100 mA/div
ILOAD 100 mA/div
20 ms/div VOUT = 3.0 V COUT = 1 mF ILOAD = 1 to 150 mA trise = 2 msec
20 ms/div VOUT = 3.0 V COUT = 1 mF ILOAD = 150 to 1 mA tfall = 2 msec
LineTransient Response-1
LineTransient Respons-2
VOUT 10 mV/div VOUT 10 mV/div
VIN 2 V/div
VIN 2 V/div
20 ms/div VINSTEP = 4 to 5 V VOUT = 3 V COUT = 1 mF CIN = 1 mF ILOAD = 150 mA trise = 5 msec
20 ms/div VINSTEP = 5 to 4 V VOUT = 3 V COUT = 1 mF CIN = 1 mF ILOAD = 150 mA tfall = 5 msec
Document Number: 72013 S-51147--Rev. F, 20-Jun-05
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Si91872
Vishay Siliconix
TYPICAL WAVEFORMS
Output Noise
10
Noise Spectrum
VOUT 200 mV/div
Output Spectral Noise Density
mV
Hz
0.01 4 ms/div VIN = 4 V VOUT = 3 V IOUT = 150 mA BW = 10 Hz to 100 kHz 10 Hz VIN = 4 V VOUT = 3 V ILOAD = 150 mA 1 MHz
FUNCTIONAL BLOCK DIAGRAM
Si91872
VIN Reverse Polarity Protection
Reference
- +
VOUT Thermal Sensor
Current Limit ERROR SD Shutdown Control
GND
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Document Number: 72013 S-51147--Rev. F, 20-Jun-05
Si91872
Vishay Siliconix
DETAILED DESCRIPTION
The Si91872 is a low-noise, low drop-out and low quiescent current linear voltage regulator, packaged in a small footprint MLP33-5 package. The Si91872 can supply loads up to 300 mA. As shown in the block diagram, the circuit consists of a bandgap reference, error amplifier, p-channel pass transistor and feedback resistor string. Additional blocks, not shown in the block diagram, include a precise current limiter, reverse battery and current protection, and thermal sensor. Thermal Overload Protection The thermal overload protection limits the total power dissipation and protects the device from being damaged. When the junction temperature exceeds 150_C, the device turns the p-channel pass transistor off. Reverse Battery Protection The Si91872 has a battery reverse protection circuitry that disconnects the internal circuitry when VIN drops below the GND voltage. There is no current drawn in such an event. When the SD pin is hardwired to VIN, the user must connect the SD pin to VIN via a 100-kW resistor if reverse battery protection is desired. Hardwiring the SD pin directly to the VIN pin is allowed when reverse battery protection is not desired. ERROR ERROR is an open drain output that goes low when VOUT is less than 4% of its normal value. To obtain a logic level output, connect a pull-up resister from ERROR to VOUT or any other voltage equal to or less than VIN. ERROR pin is high impedance (off) when SD pin is low. Auto-Discharge VOUT has an internal 100-W (typ.) discharge path to ground when SD pin is low for the Si91872. Stability The circuit is stable with only a small output capacitor equal to 6 nF/mA (= 2 mF @ 300 mA). Since the bandwidth of the error amplifier is around 1-3 MHz and the dominant pole is at the output node, the capacitor should be capacitive in this range, i.e., for 150-mA load current, an ESR <0.2 W is necessary. Parasitic inductance of about 10 nH can be tolerated. Safe Operating Area The ability of the Si91872 to supply current is ultimately dependent on the junction temperature of the pass device. Junction temperature is in turn dependent on power dissipation in the pass device, the thermal resistance of the
I OUT (A) 0.35 0.30 0.25 0.20 0.15 0.10 0.05 (VIN - VOUT)MAX = 5.3 V 0.00 0 1 2 3 VIN - VOUT (V) 4 5 6 TA = 50_C TA = 70_C
package and the circuit board, and the ambient temperature. The power dissipation is defined as PD = (VIN - VOUT) * IOUT . Junction temperature is defined as TJ = TA + ((PD * (RJC + RCA)). To calculate the limits of performance, these equations must be rewritten. Allowable power dissipation is calculated using the equation PD = (TJ - TA )/ (RJC + RCA) While allowable output current is calculated using the equation IOUT = (TJ - TA )/ (RJC + RCA) * (VIN - VOUT). Ratings of the Si91872 that must be observed are TJmax = 125 _C, TAmax = 85 _C, (VIN - VOUT)max = 5.3 V, RJC = 8 _C/W. The value of RCA is dependent on the PC board used. The value of RCA for the board used in device characterization is approximately 46 _C/W. Figure 1 shows the performance limits graphically for the Si91872 mounted on the circuit board used for thermal characterization.
TA = 85_C
Figure 1. Safe Operating Area
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Technology and Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and reliability data, see http://www.vishay.com/ppg?72013. Document Number: 72013 S-51147--Rev. F, 20-Jun-05 www.vishay.com
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