Datasheet L6932D1.2, L6932D2.5, L6932D1.8 Datasheet (SGS Thomson Microelectronics)

HIGH PERFORMANCE 2A ULDO LINEAR REGULATOR

■ 2V TO 14V INPUT VOLTAGE RANGE

■ 200mΩ Rdson MAX.

■ 200µA QUIESCENT CURRENT AT ANY LOAD

■ EXCELLENT LOAD AND LINE REGULATION

■ 1.8V AND 2.5V FIXED VOLTAGE

■ ADJUSTABLE FROM 1.2V TO 5V (L6932D1.2)

■ 1% VOLTAGE REGULATION ACCURACY

■ SHORT CIRCUIT PROTECTION

■ THERMAL SHUT DOW N

■ SO-8 (4+4) PACKAGE

APPLICATIONS

■ MOTHERBOARDS

■ MOBILE PC

■ HAND-HELD INSTRUMENTS

■ PCMCIA CARDS

■ PROCESSORS I/O

■ CHIPSET AND RAM SUPPLY

DESCRIPTION

The L6932 Ultra Low Drop Output linear regulator op­erates from 2V to 14V and is able to su pport 2A. De­signed with an internal 50m

Ω

N-channel

L6932

SO-8 (4+4)

ORDERING NUMBERS:
L6932D1.2 (SO-8 ) L6932D1.2TR (T&R)
L6932D1.8 (SO-8 ) L6932D1.8TR (T&R)
L6932D2.5 (SO-8 ) L6932D2.5TR (T&R)

Mosfet, can be usefull for the DC-DC conversion be­tween 2.5V and 1.8V at 2A in portable applications
reducing the power dissipation.

L6932 is available in 1.8V, 2.5V and adj version from

1.2V and ensure a voltage regulation accuracy of
1%.

The current limit is fix ed at 2.5A to contr ol the current
in short circuit condition within ±8%. The current is
sensed in the power mos in order to limit the power
dissipation.

The device is also provided of a thermal shut down
that limits the internal temperature at 150°C with an
histeresys of 20°C. L6932 provides the Enable and
the Power good functions.

TYPICAL OPERATING CIRCUIT

VIN

2V to 14V

VIN

2V to 14V

February 2003

IN

2

L6932D

C1 C2

5,6,7,8

IN

2

1

GND

L6932D1.2

C1

5,6,7,8

1

GND

EN

EN

OUT

3

PGOOD

4

OUT

4

ADJ

3

1.8V or 2.5V

R1

R2

VOUT

VOUT

1.2V to 5V

C2

1/10

L6932

PIN CONNECTIONS

EN

IN

ADJ

OUT 5

1
2
3
4

L6932D1.2

8
7
6

GND
GND
GND
GND

EN

IN

OUT

PGOOD 5

1
2
3
4

L6932D1.8
L6932D2.5

8
7
6

GND
GND
GND
GND

PIN FUNCTION

N°

L6232D

1.2

1 EN Enables the device if connected to Vin and disables the device if forced to gnd.
2 IN Supply voltage. This pin is connected to the drain of the internal N-mos. Connect this

ADJ – Connecting this pin to a voltage divider it is possible to programme the output voltage

3

OUT – Regulated output voltage. This pin is connected to the source of the internal N-mos.

4

L6232D

1.8/2.5

Description

pin to a capacitor larger than 10µF.

between 1.2V and 5V.

– OUT Regulated output voltage. This pin is connected to the source of the internal N-mos.

Connect this pin to a capacitor of 10µF.

Connect this pin to a capacitor of 10µF.

– PGOOD Power good output. The pin is open drain and detects the output voltage. It is forced

low if the output voltage is lower than 90% of the programmed voltage.

5, 6, 7, 8 GND Ground pin.

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

in

VIN and Pgood 14.5 V
EN, OUT and ADJ -0.3 to (Vin +0.3) V

THERMAL DATA

Symbol Parameter Value Unit

R

th J-amb

T

max

T

stg

(*) Measured on Demoboard with about 4 cm2 of dissipating area 2 Oz.

2/10

Thermal Resistance Junction to Ambient 62 (*) °C/W
Maximum Junction Temperature 150 °C
Storage Temperature Range -65 to 150 °C

L6932

BLOCK DIAGRAM

GND

ELECTRICAL CHARACTERISTCS

(*) Specification referred to T

(Referred to the Fixed Voltage version)

IN

REFERENCE

VREF=1.25V

ENABLEEN

THERMAL

SENSOR

(Tj = 25°C, VIN = 5V unless otherwise specified)

from -25°C to 125°C.

j

VREF

0.9 VREF

+

­ERROR

AMPL.

CHARGE

PUMP

­+

CURRENT

LIMIT

DRIVER

OUT

PG

D99IN1100

Symbol Parameter Test Condition Min. Typ. Max. Unit

V
V

R

I

I

V

Operating Supply Voltage 2 14 V

in

Output voltage L6932D1.2 Io = 0.1A; Vin = 3.3V 1.188 1.2 1.212 V

o

Output voltage L6932D1.8 I
Output voltage L6932D2.5 I
L6932D1.2

Line Regulation

L6932D1.8
Line Regulation

L6932D2.5
Line Regulation

L6932D1.2 Load Regulation V
L6932D1.8 Load Regulation V
L6932D2.5 Load Regulation V
Drain Source ON resistance 200 mΩ

dson

Current limiting 2.3 2.5 2.7 A

occ

Quiescent current 0.2 0. 4 mA

I

q

Shutdown current 2V < Vin < 14V

sh

Ripple Rejection f = 120Hz, I

EN Input Threshold 0.5 0.65 0.8 V

en

= 0.1A; Vin = 3.3V 1.782 1.8 1.818 V

o

= 0.1A; Vin = 3.3V 2.475 2.5 2.525 V

o

V

= 2.5V ±10%; Io = 10mA 5 mV

in

= 3.3V ±10%; Io = 10mA 5 mV

V

in

= 5V ±10%; Io = 10mA 5 mV

V

in

V

= 2.5V ±10%; Io = 10mA 5 mV

in

= 3.3V ±10%; Io = 10mA 5 mV

V

in

= 5V ±10%; Io = 10mA 5 mV

V

in

V

= 3.3V ±10%; Io = 10mA 5 mV

in

= 5V ±10%; Io = 10mA 5 mV

V

in

= 3.3V; 0.1A < Io < 2A 15 mV

in

= 3.3V; 0.1A < Io < 2A 15 mV

in

= 3.3V; 0.1A < Io < 2A 15 mV

in

*

= 1A

V

= 5V, ∆Vin = 2Vpp

in

o

60 75 dB

25 µA

3/10

L6932

ELECTRICAL CHARACTERISTCS

(continued)

Symbol Parameter Test Condition Min. Typ. Max. Unit

Pgood threshold Vo rise 90 %Vo
Pgood Hysteresis 10 %Vo
Pgood saturation I

Figure 1. Out put V ol t age v s. Junction

Temperature (L6932D1.2)

1.213

1.212

1.212

1.211

V

1.211

1.210

1.210

1.209

-60 -40 -20 0 20 40 60 80 100 120 140 160

Temp [°C]

Figure 2. Out put V ol t age v s. Junction

Temperature (L6932D1.8)

=1mA 0.2 0.4 V

pgood

Figure 4. Quiescent Current vs. Junction

Temperature

310

300

Vin=5V

290

Iq

280

(uA)

270

260

250

-40 -20 0 20 40 60 80 100 120 140
Temp [°C ]

Figure 5. Shutdown Curr ent v s. Junc ti on

Temperature

1.808

1.804

1.800

V

1.796

1.792

1.788

-60 -40 -20 0 20 40 60 80 100 120 140 160

Temp [°C]

Figure 3. Out put V ol t age v s. Junction

Temperature (L6932D2.5)

2.520

2.515

2.510

V

2.505

2.500

7.5

7

6.5

Ishdn

(uA)

Vin=5V

6

5.5

5

4.5

4

-40 -20 0 20 40 60 80 100 120 140

Temp [°C ]

4/10

2.495

-60 -40 -20 0 20 40 60 80 100 120 140 160

Temp [°C]

APPLICATION INFORMATIONS

APPLICATION CIRCUIT

In figure 6 the schematic circuit of the demoboards are shown.

Figure 6. Dem ob oards Schem atic Circui t

L6932

VIN

IN

2

OUT

3

VOUT=2.5V/1.8V

L6932D2.5

VIN

EN

C1

IN

2

1

5

L6932D1.2

6

GND

7

EN

C1

4

3

8

1

5

GND

OUT

ADJ

L6932D1.8

6

VOUT=1.2V TO 5V

R1

R2

PGOOD

4

8

7

C2

V

C2

OUT

1.2

------- -

R2

COMPONENT LIST

Fixed version

Reference Part Number Description Manufacturer

R1 R2+()⋅=

C1 C34Y5U1E106Z 10uF, 25V TOKIN
C2 C34Y5U1E106Z 10uF, 25V TOKIN

Figure 7. Demoboard Lay out (Fi xe d Versi on)

5/10

L6932

Adjustable version

Reference Part Number Description Manufacturer

C1 C34Y5U1E106Z 10uF, 25V TOKIN
C2 C34Y5U1E106Z 10uF, 25V TOKIN
R1 5.6K, 1%, 0.25W Neohm
R2 3.3K, 1%, 0.25W Neohm

Figure 8. Dem ob oard Layout (A dj ust able Versio n)

COMPONENTS SELECTION
Input Capacitor

The input capacitor value depends on a lot of facto rs such as load transient r equi rements, input s ource ( battery
or DC/DC converter) and its distance from the input cap. Usually a 47

µ

F is enough for any application but a

much lower value can be sufficient in many cases.

Output Capacitor

The output capacitor choice depends basically on the load transient requirements.
Tantalum, Speciality Polimer, POSCAP and aluminum capacitors are good and offer very low ESR values.
Multilayer ceramic caps have the lowest ESR and can be r equired for particular applications. Nevertheless in

several applications they are ok, the loop stability issue has to be considered (see loop stability section).
Below a list of some suggested capacitor manufacturers.

Manufacturer Type Cap Value (µF) Rated Voltage (V)

PANASONIC CERAMIC 1 to 47 4 to 16
TAYO YUDEN CERAMIC 1 to 47 4 to 16
TDK CERAMIC 1 to 47 4 to 16
TOKIN CERAMIC 1 to 47 4 to 16
SANYO POSCAP 1 to 47 4 to 16
PANASONIC SP 1 to 47 4 to 16
KEMET TANTALUM 1 to 47 4 to 16

6/10

Loop Stability

The stability of the loop is affected by the zero introduced by the output capacitor.
The time constant of the zero is given by:

L6932

T ESR C

⋅= F

OUT

ZERO

--------------------------------------------=

2π ESR C

1

⋅⋅

OUT

This zero helps to increase the phase margin of the loop until the time constant is higher than some hundreds
of nsec, depending also on the output voltage and current.

So, using very low ESR ceramic capaci tors could produce oscillations at the output, in particular when regul ating
high output voltages (adjustable version).

To solve this issue is sufficient to add a small capacitor (e.g. 1nF to 10nF) in parallel to the high side resistor of
the external divider, as shown in figure 9.

Figure 9. Comp e nsation Network

VIN=2V TO 14V

C1

IN

EN

2

1

5

L6932D1.2

6

GND

OUT

4

R1

ADJ

3

8

7

R2

VOUT=1.2V TO 5V UP to 2A

C3

C2

Thermal Considerations

Since the device is housed in a small SO(4+2+2) package the thermal issue can be the bottleneck of many ap­plications. The power dissipated by the device is given by:

P

DISS

= (VIN - V

OUT

) · I

OUT

The thermal resistance junction to ambient of the demoboard is approximately 62°C/W. This mean that, consid­ering an ambient temperature of 60°C and a maximum junction temperature of 150°C, the maximum power that
the device can handle is 1.5W.

This means that the device is able to deliver a DC output current of 2A only with a very low dropout.
In many applications, high output current pulses are required. If their duration is shorter than the thermal con-

stant time of the board, the thermal impedance (not the thermal resistance) has to be considered.
In figure 10 the thermal impedance versus the duration of the current pulse for the SO(4+2+2) mounted on board

is shown.

7/10

L6932

Figure 10. Thermal Impedance

Considering a pulse duration of 1sec, the thermal impedance is close to 20°C/W, allowing much bigger power
dissipated.

Example:

Vin = 3.3V
Vout = 1.8V
Iout = 2A
Pulse Duration = 1sec

The power dissipated by the device is:

P

DISS

= (VIN - V

OUT

) · I

OUT

= 1.5 · 2 3W

Considering a thermal impedance of 20°C/W, the maximum junction temperature will be:

= TA + Z

T

J

THJA

· P

= 60 + 60 = 120°C

DISS

Obviously, with pulse durations longer than approximately 10sec the thermal impedance is very close to the
thermal resistance (60°C/W to 70°C/W).

8/10

L6932

DIM.

D (1) 4.8 5.0 0.189 0.197

F (1) 3.8 4.0 0.15 0.157

(1) D and F do not include mold flash or protrusions. Mold flash or
potrusions shall not exceed 0.15mm (.006inch).

MIN. TYP. MAX. MIN. TYP. MAX.

A 1.75 0.069
a1 0.1 0.25 0.004 0.010
a2 1.65 0.065
a3 0.65 0.85 0.026 0.033

b 0.35 0.48 0.014 0.019

b1 0.19 0.25 0.007 0.010

C 0.25 0.5 0.010 0.020
c1 45° (typ.)

E 5.8 6.2 0.228 0.244

e 1.27 0.050

e3 3.81 0.150

L 0.4 1.27 0.016 0.050

M 0.6 0.024

S8° (max.)

mm inch

OUTLINE AND

MECHANICAL DATA

SO8

9/10

L6932

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