Document
Data Sheet No. PD94129 revA
IRU1150(PbF)
4A ULTRA LOW DROPOUT POSITIVE ADJUSTABLE REGULATOR DESCRIPTION
The IRU1150 is a 4A regulator with extremely low dropout voltage using a proprietary bipolar process that achieves comparable equivalent on-resistance to that of discrete MOSFETs. This product is specifically designed to provide well regulated supply for applications requiring 2.8V or lower voltages from 3.3V ATX power supplies where high efficiency of a switcher can be achieved without the cost and complexity associated with switching regulators. One such application is the new graphic chip sets that require anywhere from 2.4V to 2.7V supply such as the Intel I740 chip set.
FEATURES
0.7V Dropout at 4A Fast Transient Response 1% Voltage Reference Initial Accuracy Built-In Thermal Shutdown
APPLICATIONS
3.3V to 2.7V Intel I740 Chip Set
TYPICAL APPLICATION
3.3V
C1 100uF
VIN VCTRL
5 4 3 2 1
R1 102 R2 118 C3 100uF
IRU1150
VOUT Adj VSENSE
2.7V
5V
C2 100uF
Figure 1 - Typical application of IRU1150 in a 3.3V to 2.7V for I740 chip.
PACKAGE ORDER INFORMATION
Basic Part (Non-Lead Free)
TJ (°C) 0 To 125 5-PIN PLASTIC TO-263 (M) IRU1150CM 5-PIN PLASTIC Ultra Thin-PakTM (P) IRU1150CP 8-PIN PLASTIC SOIC (S) IRU1150CS
Leadfree Part
TJ (°C) 0 To 125 5-PIN PLASTIC TO-263 (M) Not available 5-PIN PLASTIC Ultra Thin-PakTM (P) Not available 8-PIN PLASTIC SOIC (S) IRU1150CSPbF
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1
IRU1150(PbF)
ABSOLUTE MAXIMUM RATINGS
Input Voltage (VIN) .................................................... 7V Control Input Voltage (VCTRL) ..................................... 14V Power Dissipation ..................................................... Internally Limited Storage Temperature Range ...................................... -65°C To 150°C Operating Junction Temperature Range ..................... 0°C To 150°C
PACKAGE INFORMATION
5-PIN PLASTIC TO-263 (M)
FRONT VIEW 5
5-PIN PLASTIC ULTRA THIN-PAKTM (P)
FRONT VIEW 5
8-PIN PLASTIC SOIC (S)
TOP VIEW
Tab is V OUT
4 3 2 1
VIN VCTRL VOUT Adj VSENSE
Tab is V OUT
4 3 2 1
VIN VCTRL VOUT Adj VSENSE
VCTRL VIN Adj VSENSE
1 2 3 4
8 7 6 5
VOUT VOUT VOUT VOUT
θJA=35°C/W for 0.5" square pad
θJA=35°C/W for 0.5" square pad
θJA=55°C/W for 1" Sq pad area
ELECTRICAL SPECIFICATIONS
Unless otherwise specified, these specifications apply over CIN=1µF, COUT=10µF, and TJ=0 to 125 C. Typical values refer to TJ=25 C. VOUT=VSENSE. PARAMETER Reference Voltage Line Regulation Load Regulation (Note 1) Dropout Voltage (Note 2) (VCTRL - VOUT) SYM VREF TEST CONDITION
VCTRL=2.7 to 12V, VIN=2.05V to 5.5V,
MIN 1.225 -5 -5
TYP 1.250 -0.2 3 1.00 1.05 1.13 0.26 0.50 0.70
MAX 1.275 +5 +5 1.15 1.15 1.20 0.38 0.60 1.15 6 10
UNITS V mV mV V
Io=10mA to 4A, VADJ=0V
VCTRL=2.5V to 7V, VIN=1.75V to 5.5V,
Dropout Voltage (Note 2) (VIN - VOUT)
Current Limit Minimum Load Current (Note 3) Thermal Regulation Ripple Rejection Control Pin Current
Adjust Pin Current
IADJ
Io=10mA, VADJ=0V VCTRL=2.75V, VIN=2.1V, Io=10mA to 4A, VADJ=0V VADJ=0V for all conditions below: VIN=2.05V, Io=1.5A VIN=2.05V, Io=3A VIN=2.05V, Io=4A VADJ=0V for all conditions below: VCTRL=2.75V, Io=1.5A VCTRL=2.75V, Io=3A VCTRL=2.75V, Io=4A VCTRL=2.75V, VIN=2.05V, ∆Vo=100mV, VADJ=0V VCTRL=5V, VIN=3.3V, VADJ=0V 30ms Pulse VCTRL=5V, VIN=5V, Io=4A, VADJ=0V, TJ=25 C, VRIPPLE=1VPP at 120Hz VADJ=0V for all below conditions: VCTRL=2.75V, VIN=2.05V, Io=1.5A VCTRL=2.75V, VIN=2.05V, Io=3A VCTRL=2.75V, VIN=2.05V, Io=4A VCTRL=2.75V, VIN=2.05V, VADJ=0V
V
4.2
4.65 1 0.01 70 16 36 67 50
A mA %/W dB
25 50 85
mA
µA
2
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IRU1150(PbF)
Note 1: Low duty cycle pulse testing with Kelvin connections is required in order to maintain accurate data. Note 2: Dropout voltage is defined as the minimum differential between VIN and VOUT required to maintain regulation at VOUT. It is measured when the output voltage drops 1% below its nominal value. Note 3: Minimum load current is defined as the minimum current required at the output in order for the output voltage to maintain regulation. Typically the resistor dividers are selected such that it automatically maintains this current.
PIN DESCRIPTIONS
PIN # 1 2 3 4 PIN SYMBOL PIN DESCRIPTION VSENSE This pin is the positive side of the reference which allows remote load sensing to achieve excellent load regulation. Adj VOUT VCTRL A resistor divider from this pin to the VOUT pin and ground sets the output voltage. The output of the regulator. A minimum of 10µF capacitor must be connected from this pin to ground to insure stability. This pin is the supply pin for the internal control circuitry as well as the base drive for the pass transistor. This pin must always be higher than the VOUT pin in order for the device to regulate. (See specifications) The input pin of the regulator. Typically a large storage capacitor is connected from this pin to ground to insure that the input voltage does not sag below the minimum drop out voltage during the load transient response. This pin must always be .