DEVICE DESCRIPTION
The ZLDO Series low dropout linear
regulators operate with an exceptionally
low dropout voltage, typically only 30mV
with a load current of 100mA. The regulator
series features output voltages in the range
2.7 to 18 volts, this device provides an output
voltage of 3.3 volts.
The ZLDO330 consumes a typical quiescent
current of only 560
A and is rated to supply
load currents up to 300mA. A battery low flag
is available to indicate potential power fail
situations. If the input voltage falls to within
300mV of the regulated output voltage then
the error output pulls low. The device also
features an active high disable control. Once
disabled the ZLDO quiescent current falls to
typically 11
A.
The ZLDO devices are packaged in Zetex
SM8 8 pin small outline surface mount
package, ideal for applications where space
saving is important. The device low dropout
voltage, low quiescent current and small size
make it ideal for low power and battery
powered applications. Battery powered
circuits can make particular use of the low
battery flag and shutdown features.
FEATURES
Very low dropout voltage
6mV dropout at 10mA output
30mV dropout at 100mA output
100mV dropout at 300mA output
3.3 volt fixed output
Other voltages available
Low quiescent current
1mA quiescent (typ) at 300mA output
Low battery flag
Shutdown control
Surface mount package
APPLICATIONS
Battery powered devices
Portable instruments
Portable communications
Laptop/Palmtop computers
Electronic organisers
3.3 VOLT ULTRA LOW DROPOUT
REGULATOR
ISSUE 2 - MAY 1997
ZLDO330
LOW BATTERY
COMPARATOR
Low Battery Flag
Vin
OUTPUT
DRIVE
BIAS
CIRCUIT
SHUTDOWN
THERMAL
SHUTDOWN
Shutdown
Control
BANDGAP
REFERENCE
Vo
Shaping
Gnd
Cs
4-62
ABSOLUTE MAXIMUM RATING
Input Supply
Voltage Range
-0.3 to 20V
Shutdown Input
Voltage Range
-0.3 to Vin
Low Battery Output
Voltage Range
-0.3 to 20V
Output Current
300mA
Operating Temperature
-40 to 85C
Storage Temperature
-55 to 150C
Power Dissipation
(Tamb=25C)
2W (Note 1)
ZLDO330
ELECTRICAL CHARACTERISTICS
TEST CONDITIONS (Unless otherwise stated) T
amb
=25C,I
L
=10mA,C
s
=10pF,C
out
=1
F
Parameter
SYMBOL CONDITIONS
MIN.
TYP.
MAX. UNITS
Output voltage
V
o
V
in
=4.3V
3.2
3.3
3.4
V
Output voltage
temperature coefficient
V
o
T
V
in
=4.3V
(Note 2, Note 4)
100
250
ppm/C
Line regulation
V
o
V
in
=4.3 to 20V
15
52
mV
Load regulation
V
o
I
L
=10 to 300mA
V
in
=4.3V
45
78
mV
Dropout voltage
(Note3)
V
in
-V
o
I
L
=10mA
I
L
=100mA
I
L
=300mA
6
30
100
10
75
200
mV
Quiescent current
I
q
V
in
=4.3V, I
L
=0
0.56
1
mA
Quiescent current
at shutdown
I
qs
V
in
=4.3V, I
L
=0,
V
shdn
=V
in
11
30
A
Shutdown control
input
current
I
ins
V
shdn
=V
in
=4.3V
2
10
A
Shutdown control
threshold voltage
V
ts
V
in
=4.3V
low(on)
high(off)
1.5
0.4
V
Output current in
shutdown mode
(Note4)
I
Ls
V
in
=20V
V
o
=Gnd
50
100
nA
Output noise voltage
(Note4)
e
n
V
in
=4.3V
f=10Hz to100kHz,
I
L
=100mA
190
V RMS
Low battery detect
threshold
V
in(bld)
V
out
+
0.2V
V
out
+
0.4V
V
Low battery flag
output voltage
V
bl
I
bl
=100
A,
V
in
<V
o
+200mV
0.16
0.4
V
Low battery flag
leakage current
I
bl
V
bl
=6V,
V
in
>V
o
+400mV
0.1
1
A
4-63
ZLDO330
PIN DEFINITIONS
Pin 1 LBF - Low Battery Flag. An open collector
NPN output which pulls low on failing input
supply.
Pin 2 SC - Shutdown Control. This high
impedance logic compatible input disables the
regulator when taken high. It includes a diode
wired to Vin and so will pass current if taken more
than 0.5V above Vin.
Pin 3 Vin - Voltage Input. The power supply to
the regulator. The permissible input voltage
range is -0.3 to 20V. An input capacitor is not
mandatory but will be useful in reducing the
coupling of noise from input to output and
minimising the effect of sudden changes in load
current on the input voltage.
Pin 4 N/C - Not Connected. Not internally
connected and so can be left open or wired to
any pin without affecting the performance of the
regulator.
Pin 5 Vout - Voltage Output. The output of the
regulator. An output capacitor of 1uF or greater
and having low ESR should be wired in close
proximity to the regulator to ensure stability for
all loads.
Pin 6 D/C - Do Not Connect. This pin is wired to
an internal circuit node of the regulator. No
external connection should be made to this pin.
Pin 7 Gnd - Ground. The ground connection of
the regulator against which the output voltage is
referenced.
Pin 8 Spg - Shaping. The shaping node for
the error amplifier of the regulator. A capacitor
of 10pF wired from this pin to the output pin
(pin 5) gives optimum stability. Improved AC
can be achieved by reducing the value of this
capacitor but stability may be impaired for
some load conditions.
FUNCTIONAL DESCRIPTION
The ZLDO is a high performance, ultra low dropout, low quiescent regulator. Available in SM8 surface
mount packaging, the device is able to dissipate 2W(note 1) allowing complete design flexibility with
an input span upto 20V and 300mA output current. The device quiescent is 1mA (typ) at 300mA load
current. A low battery comparator signifies impending battery failure, whilst a shutdown function
reduces quiescent current to a mere 11
A (typ). A precision bandgap reference gives
2.5% output
tolerance and good temperature characteristics over the range -40 to +85C. AC performance is
enhanced via the use of a small external capacitor.
NOTES.
1. Maximum power dissipation of the device is calculated assuming the package is mounted on a PCB
measuring 2 inches square.
2 Output voltage temperature coefficient is calculated as:-
V
O
change x
1000000
V
O
x temperature change
3. Dropout voltage is defined as the input to output voltage differential at which the circuit ceases to
regulate. The value is measured when the output voltage has dropped by 100mV from V
out
measured
at the nominal input V
in
= V
out
+ 1V
4. Guaranteed by design.
4-64
ZLDO330
Temperature ( C)
Quiescent Current vs. Temperature
Temperature ( C)
Shutdown Current vs. Temperature
Temperature ( C)
O
u
tput V
olt
a
g
e
(V)
Output Voltage Temperature Coefficient
Io=10mA
Q
u
iesce
nt C
urr
ent (
A)
V(in)=5V
V(in)=5V
S
hutdo
wn C
urre
n
t
(
A)
O
u
tput I
m
ped
ance
(m
)
Frequency (Hz)
Output Impedance vs. Frequency
Ri
pple R
e
j
e
ction
(dB)
Frequency (Hz)
Ripple Rejection vs. Frequency
L.
B.F
.
O
per
atio
n
V
o
ltage
(V)
Temperature ( C)
Low Battery Flag Operating Point
35
40
45
50
55
30
25
20
15
10
5
0
100
1K
10K
100K
400
440
480
520
560
600
640
680
-40
0
-20
20
40
60
80
3.28
3.30
3.27
3.32
3.29
-40
-20
0
20
60
40
80
10
12
16
14
8
-20
-40
0
80
20
40
60
6
3.56
3.57
3.58
3.61
3.60
3.59
-40
-20
0
20
60
40
80
0
200
400
600
800
1000
1200
1400
100K
100
10K
1K
C
(out)
=1
F
10pF
4.7pF
2.2pF
C
(out)
=1
F
10pF
4.7pF
2.2pF
100
V(in)=7V
Io=10mA
3.55
100
V(in)=5V
3.31
3.33
100
TYPICAL CHARACTERISTICS
4-65
ZLDO330
Time (
s)
Line Transient Response
Time (
s)
O
utput V
o
l
tag
e
D
e
v
i
ation
(V)
Load Transient Response
0
0
200
400
600
1000
800
0
-0.4
-0.2
0.2
120
0
40
80
200
160
O
utput V
o
l
tag
e
D
e
v
i
ation
(V)
D
ropo
ut V
olta
ge
(mV
)
Load Current (mA)
Dropout Voltage vs. Load Current
40
60
80
100
120
20
0
0.1
1.0
10
100
1000
0.4
-0.4
0.8
85 C
25 C
-40 C
V
(in)
=10V
V
(in)
=5V
Io=100mA
1.0
0.1
0.01
SINGLE PULSE TEST T
amb
= 25 C
Lo
ad Curr
ent
(A
M
P
S
)
Input-Output Differential Voltage (VOLTS)
Safe Operating Area
2
5
10
20
1
Operation in shaded area is not guaranteed
Output Voltage Deviation
V
(in)
=5V
I
O
=100mA
I
O
=0mA
Output Voltage Deviation
DC
1s
0.1s
10ms
TYPICAL CHARACTERISTICS
4-66
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