International Rectifier IRU1030CD, IRU1030CT, IRU1030CM Datasheet
Data Sheet No. PD94124
IRU1030
3A LOW DROPOUT POSITIVE
ADJUSTABLE REGULATOR
FEATURES
Guaranteed < 1.3V Dropout at Full Load Current
Fast Transient Response
1% Voltage Reference Initial Accuracy
Output Current Limiting
Built-In Thermal Shutdown
APPLICATIONS
Low Voltage Processor Applications such as:
P54C, P55C, Cyrix M2,
POWER PC, AMD
GTL+ Termination
PENTIUM PRO, KLAMATH
Low Voltage Memory Termination Applications
Standard 3.3V Chip Set and Logic Applications
TYPICAL APPLICATION
5V
C1
1500uF
Vin
3
DESCRIPTION
The IRU1030 is a low dropout three-terminal adjustable
regulator with minimum of 3A output current capability.
This product is specifically designed to provide well regulated supply for low voltage IC applications such as
Pentium P54C, P55C as well as GTL+ termination for Pentium Pro and Klamath processor appli-
cations. The IRU1030 is also well suited for other pro-
cessors such as Cyrix, AMD and Power PC appli-
cations. The IRU1030 is guaranteed to have <1.3V dropout at full load current making it ideal to provide well
regulated outputs of 2.5V to 3.3V with 4.75V to 7V input
supply.
Vou t
Adj
2
R1
121
1
R2
200
IRU1030
1030app1-1.1
Figure 1 - Typical Application of IRU1030 in a 5V to 3.3V regulator
Notes: Pentium P54C, P55C, Klamath, Pentium Pro, VRE are trademarks of Intel Corp.Cyrix M2 is trademark of Cyrix Corp.
Power PC is trademark of IBM Corp.
3.3V / 3A
C2
1500uF
PACKAGE ORDER INFORMATION
Tj (°C) 3-PIN PLASTIC 3-PIN PLASTIC 2-PIN PLASTIC
TO-220 (T) TO-263 (M) TO-252 (D-Pak)
0 To 150 IRU1030CT IRU1030CM IRU1030CD
Rev. 1.1
06/29/01
1
IRU1030
ABSOLUTE MAXIMUM RATINGS
Input Voltage (Vin) .................................................... 7V
Power Dissipation ..................................................... Internally Limited
Storage Temperature Range ...................................... -65°C To 150°C
Operating Junction Temperature Range ..................... 0°C To 150°C
PACKAGE INFORMATION
3-PIN PLASTIC TO-220 (T) 3-PIN PLASTIC TO-263 (M) 2-PIN PLASTIC TO-252 (D-Pak)
Vou t
FRONT VIEW
3
Vin
2
Vou t
1
Adj
Tab is
Vou t
FRONT VIEW
3
2
1
Vin
Vou t
Adj
Tab i s
θJT=2.7°C/W θJA=60°C/W θJA=35°C/W for 1" Square pad θJA=70°C/W for 0.5" Square pad
ELECTRICAL SPECIFICATIONS
Unless otherwise specified, these specifications apply over Cin=1µF, Cout=10µF, and Tj=0 to 150!C.
Typical values refer to Tj=25!C.
PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS
Reference Voltage Vref Io=10mA, Tj=25!C, (Vin-Vo)=1.5V 1.238 1.250 1.262 V
Io=10mA, (Vin-Vo)=1.5V 1.225 1.250 1.275
Line Regulation Io=10mA, 1.3V<(Vin-Vo)<7V 0.2 %
Load Regulation (Note 1) Vin=3.3V, Vadj=0, 10mA<Io<3A 0.4 %
Dropout Voltage (Note 2) ∆Vo Note 2, Io=3A 1.1 1.3 V
Current Limit Vin=3.3V, dVo=100mV 3.1 A
Minimum Load Current Vin=3.3V, Vadj=0V 5 10 mA
(Note 3)
Thermal Regulation 30ms Pulse, Vin-Vo=3V, Io=3A 0.01 0.02 %/W
Ripple Rejection f=120Hz, Co=25µF Tantalum,
Io=1.5A, Vin-Vo=3V 60 70 dB
Adjust Pin Current Iadj Io=10mA, Vin-Vo=1.5V, Tj=25!C,
Io=10mA, Vin-Vo=1.5V 55 120 µA
Adjust Pin Current Change Io=10mA, Vin-Vo=1.5V, Tj=25!C 0.2 5 µA
Temperature Stability Vin=3.3V, Vadj=0V, Io=10mA 0.5 %
Long Term Stability Tj=125!C, 1000Hrs 0.3 1 %
RMS Output Noise Tj=25!C, 10Hz<f<10KHz 0.003 %Vo
Tab i s
Vout
FRONT VIEW
3
Vin
1
Adj
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 voltage between Vin and Vout required to maintain regulation at Vout. It is measured when the output
voltage drops 1% below its nominal value.
2
Note 3: Minimum load current is defined as the mini-
mum current required at the output in order for the output voltage to maintain regulation. Typically the resistor
dividers are selected such that this current is automatically maintained.
Rev. 1.1
06/29/01
PIN DESCRIPTIONS
PIN # PIN SYMBOL PIN DESCRIPTION
1
Adj
A resistor divider from Vout to Adj pin to ground sets the output voltage.
IRU1030
2
3
Vout
Vin
The output of the regulator. A minimum of 10µF capacitor must be connected from this pin
to ground to insure stability.
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 1.3V higher than Vout
in order for the device to regulate properly.
BLOCK DIAGRAM
Vin 3
CURRENT
LIMIT
2 Vout
+
1.25V
+
THERMAL
SHUTDOWN
Figure 2 - Simplified block diagram of the IRU1030
APPLICATION INFORMATION
Introduction
The IRU1030 adjustable Low Dropout (LDO) regulator is
a three-terminal device which can easily be programmed
with the addition of two external resistors to any voltages within the range of 1.25 to 5.5V. This regulator unlike the first generation of the three-terminal regulators
such as LM117 that required 3V differential between the
input and the regulated output, only needs 1.3V differential to maintain output regulation. This is a key requirement for today’s microprocessors that need typically
3.3V supply and are often generated from the 5V supply. Another major requirement of these microproces-
sors such as the Intel P54C is the need to switch the
load current from zero to several amps in tens of nano-
1030blk1-1.0
seconds at the processor pins, which translates to an
approximately 300 to 500ns current step at the regulator. In addition, the output voltage tolerances are also
extremely tight and they include the transient response
as part of the specification. For example Intel VRE
specification calls for a total of ±100mV including initial
tolerance, load regulation and 0 to 4.6A load step.
The IRU1030 is specifically designed to meet the fast
current transient needs as well as providing an accurate
initial voltage, reducing the overall system cost with the
need for fewer output capacitors.
1 Adj
Rev. 1.1
06/29/01
3
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