ISSUE 5 - NOVEMBER 2001
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
1
DESCRIPTION
The ZXCL series are very small low dropout
regulators designed for use in low power and
severely space limited applications.
The devices operate with a low dropout voltage,
typically of only 85mV at 50mA load. Supply current
is minimised with a ground pin current of only 50µA
at full 150mA load. Logic control allows the devices
to be shut down, consuming typically less than 10nA.
These features make the device ideal for battery
powered applications where power economy is
critical.
The parts have been designed with space sensitive
systems in mind. They are available in the ultra small
SC70 package, which is half the size of other SOT23
based regulator devices.
FEATURES
•5-pin SC70 package for the ultimate in space
saving
•5-pin SOT23 industry standard pinout
•Low 85mV dropout at 50mA load
•50µA ground pin current with full 150mA load
•Typically less than 10nA ground pin current on
shutdown
•2.5, 2.6, 2.8, 3, 3.3 and 4 volts output
•Very low noise, without bypass capacitor
•Thermal overload and over-current protection
•-40 to +85°C operating temperature range
For applications requiring improved performance
over alternative devices, the ZXCL is also offered in
the 5 pin SOT23 package with an industry standard
pinout.
The devices feature thermal overload and
over-current protection and are available with output
voltages of 2.5V, 2.6V, 2.8V, 3V, 3.3V and 4V. Other
voltage options between 1.5V and 4V can be
provided. Contact Zetex marketing for further
information.
The ZXCL series are manufactured using CMOS
processing, however advanced design techniques
mean that output noise is improved even when
compared to other bipolar devices.
APPLICATIONS
•Cellular and Cordless phones
•Palmtop and laptop computers
•PDA
•Hand held instruments
•Camera, Camcorder, Personal Stereo
•PCMCIA cards
•Portable and Battery-powered equipment
ULTRA SMALL MICROPOWER SC70 LOW DROPOUT REGULATORS
Battery Supply Output Voltage
ZXCL
TYPICAL APPLICATION CIRCUIT
PACKAGE FOOTPRINT
Total Aea
2.1mm x 2mm
=4.2mm2
Total Aea
2.8mm x 2.9mm
=8.12mm2
2
ISSUE 5 - NOVEMBER 2001
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage with respect to GND
VIN -0.3V to 7.0V
EN-0.3V to 10V
VO-0.3V to 5.5V
Output short circuit duration Infinite
Continuous Power Dissipation Internally limited
Operating Temperature Range -40°C to +85°C
Storage Temperature Range -55°C to +125°C
ELECTRICAL CHARACTERISTICS
VIN = VO+ 0.5V, typical values at TA = 25 C V (Unless otherwise stated)
SYMBOL PARAMETER CONDITIONS LIMITS UNITS
MIN TYP MAX
VIN Input Voltage (note2) 5.5 V
VOOutput Voltage IO=1mA
ZXCL250
ZXCL260
ZXCL280
ZXCL300
ZXCL330
ZXCL400
IO= 100mA
VO+0.5V<V
IN <V
IN max.
ZXCL250
ZXCL260
ZXCL280
ZXCL300
ZXCL330
ZXCL400
2.450
2.548
2.744
2.940
3.234
3.920
2.425
2.522
2.744
2.910
3.201
3.880
2.5
2.6
2.8
3.0
3.3
4.0
2.550
2.652
2.856
3.060
3.366
4.080
2.575
2.678
2.884
3.090
3.399
4.120
V
V
∆VO/∆TOutput Voltage
Temperature
Coefficient
-15 ppm/°C
IO(MAX) Output Current ZXCL250 only 150
100 mA
IOLIM Over Current Limit ZXCL250 only 160
105 230 800
750 mA
IQGround pin current No Load
IO= 150mA,
IO= 100mA,
25
50
40
50
120
100
A
A
A
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 conditions for extended periods may affect device reliability.
Package Power Dissipation (TA=25°C)
SC70 300mW (Note 1)
SOT23-5 450mW (Note 1)
ELECTRICAL CHARACTERISTICS
VIN = VO+ 0.5V, typical values at TA=25°C (Unless otherwise stated)
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
ISSUE 5 - NOVEMBER 2001
3
SYMBOL PARAMETER CONDITIONS LIMITS UNITS
MIN TYP MAX
VDO Dropout Voltage
Note 3
ZXCL250
IO=10mA
IO=50mA
IO=100mA
ZXCL260
IO=10mA
IO=50mA
IO=100mA
ZXCL280
IO=10mA
IO=50mA
IO=100mA
ZXCL300
IO=10mA
IO=50mA
IO=100mA
ZXCL330
IO=10mA
IO=50mA
IO=100mA
ZXCL400
IO=10mA
IO=50mA
IO=100mA
15
85
163
15
85
155
15
85
140
15
85
140
15
85
140
15
85
140
325
310
280
280
280
280
mV
mV
mV
mV
mV
mV
⌬VLNR Line Regulation VIN=(VO+0.5V) to 5.5V, IO=1mA 0.02 0.1 %/V
⌬VLDR Load Regulation IO=1mA to 100mA 0.01 0.04 %/mA
ENOutput Noise Voltage f=10Hz to 100kHz, CO=10µF, 50 µV rms
VENH Enable pin voltage for
normal operation TA= -40°C
2
2.2 10 V
VENL Enable pin voltage for
output shutdown 00.8V
VENHS Enable pin hysteresis 150 mV
IEN Enable Pin input
current VEN=5.5V 100 nA
IQSD Shutdown supply
current VEN=0V 1 µA
TSD Thermal Shutdown
Temperature 125 165 °C
Device testing is performed at TA=25⬚C. Device thermal performance is guaranteed by design.
Note1: Maximum power dissipation is calculated assuming the device is mounted on a PCB measuring 2
inches square
Note 2: Output Voltage will start to rise when VIN exceeds a value or approximately 1.3V. For normal
operation, VIN (min) > VOUT (nom) + 0.5V.
Note 3: Dropout voltage is defined as the difference between VIN and VO, when VOhas dropped 100mV below
4
-50 -25 0 25 50 75 100
2.79
2.80
2.81
-50 -25 0 25 50 75 100
23.0
23.2
23.4
23.6
23.8
24.0
24.2
24.4
24.6
24.8
25.0
012345
0
5
10
15
20
25
30
0 25 50 75 100 125 150
20
25
30
35
40
45
50
55
60
0123456
0
1
2
3
4
5
6
0 25 50 75 100 125 150 175
0.00
0.05
0.10
0.15
0.20
0.25
VIN =3.3V
No Load
Output Voltage v Temperature
Output Voltage (V)
Temperature (°C)
VIN =3.3V
No Load
Ground Current v Temperature
Ground Current (µA)
Temperature (°C)
No Load
Ground Current v Input Voltage
Ground Current (µA)
Input Voltage (V)
VIN =3.3V
VIN =5V
Ground Current v Load Current
Ground Current (µA)
Load Current (mA)
VIN
IOUT =100mA
IOUT =1mA
Input to Output Characteristics
Voltage (V)
Input Voltage (V) Dropout Voltage v Output Current
Dropout Voltage (V)
Output Current (mA)
ISSUE 5 - NOVEMBER 2001
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
TYPICAL CHARACTERISTICS (ZXCL280 shown)
ISSUE 5 - NOVEMBER 2001
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
5
0.0 0.1 0.2 0.3 0.4 0.5
-20
-10
0
10
20
3
4
5
6
0 102030405060708090100
0
1
2
3
4
5
6
0.0 0.1 0.2 0.3 0.4 0.5
-20
-10
0
10
20
3
4
5
6
0.0 0.1 0.2 0.3 0.4 0.5
-100
-50
0
50
100
0
50
100
10 100 1k 10k 100k 1M
0.01
0.1
1
10
10 100 1k 10k 100k 1M
0
10
20
30
40
50
60
70
80
COUT =1mF
Tr&T
f= 2.5ms
Line Rejection IL= 100mA
DV
OUT
(mV) V
IN
(V)
Time (ms)
VIN =5V
IL= 1mA
IL= 100mA
Enable
VIN = 3.3V
IL= 1mA
IL= 100mA
COUT =1mF
Start-Up Response
Voltage (V)
Time (µs)
COUT =1mF
Tr&T
f= 2.5ms
DV
OUT
(mV) V
IN
(V)
Line Rejection IL=1mA
Time (ms)
COUT =10mF
COUT =1mF
COUT =10mF
COUT =1mF
VIN =5V
IL= 1mA to 50mA
Load Response
DV
OUT
(mV) I
L
(mA)
Time (ms)
IL= 100mA, COUT =1mF
IL= 100mA, COUT =10mF
No Load, COUT =10
m
F
No Load, COUT =1mF
Output Noise v Frequency
Noise µV/√Hz
Frequency (Hz)
All Caps Ceramic
Surface Mount
IL= 50mA
COUT =1mF
COUT = 2.2mF
COUT =10mF
Power Supply Rejection v Frequency
Power Supply Rejection (dB)
Frequency (Hz)
TYPICAL CHARACTERISTICS (ZXCL280 shown)
ISSUE 5 - NOVEMBER 2001
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
6
PIN DESCRIPTION
Pin Name Pin Function
VIN Supply Voltage
GND Ground
ENActive HIGH Enable input. TTL/CMOS logic compatible.
Connect to VIN or logic high for normal operation
N/C No Connection
VORegulator Output
SC70
Package Suffix – H5
Top View
SOT23-5
Package Suffix – E5
Top View
G
ND
E
N
N/C
V
IN
V
O
1
2
34
5
G
ND
E
N
N/C
V
IN
V
O
1
2
34
5
CONNECTION DIAGRAMS
SCHEMATIC DIAGRAM
SC70
Package Suffix –H5
Top View
GND
EN
N/C
VIN
VO
1
2
34
5
ZXCLXXX ZXCL1XXXZXCLXXX
Input to Output Diode
In common with many other LDO regulators, the ZXCL
device has an inherent diode associated with the
output series pass transistor of each regulator. This
diode has its anode connected to the output and its
cathode to the input. The internal diode is normally
reverse biased, but will conduct if the output is forced
above the input by more than a VBE (approximately
0.6V). Current will then flow from Vout to Vin. For safe
operation, the maximum current in this diode should
be limited to 5mA continuous and 30mA peak. An
external schottky diode may be used to provide
protection when this condition cannot be satisfied.
Increased Output current
Any ZXCL series device may be used in conjunction
with an external PNP transistor to boost the output
current capability. In the application circuit shown
below, a FMMT717 device is employed as the external
pass element. This SOT23 device can supply up to 2.5A
maximum current subject to the thermal dissipation
limits of the package (625mW). Alternative devices
may be used to supply higher levels of current. Note
that with this arrangement, the dropout voltage will be
increased by the VBE drop of the external device. Also,
care should be taken to protect the pass transistor in
the event of excessive output current.
ISSUE 5 - NOVEMBER 2001
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
7
VIN
EN
GND
VO
U1
ZXCL SERIES
Q1
FMMT717
R1
5.6R
C2
1uF
C1
1uF
C3
1uF
VOUTVIN
Scheme to boost output current to 2A
APPLICATIONS INFORMATION
Enable Control
A TTL compatible input is provided to allow the
regulator to be shut down. A low voltage on the Enable
pin puts the device into shutdown mode. In this mode
the regulator circuit is switched off and the quiescent
current reduces to virtually zero (typically less than
10nA). A high voltage on the Enable pin ensures
normal operation.
The Enable pin can be connected to VIN or driven from
an independent source of up to 10V maximum. (e.g.
CMOS logic) for normal operation. There is no clamp
diode from the Enable pin to VIN, so the VIN pin may be
at any voltage within its operating range irrespective of
the voltage on the Enable pin.
Current Limit
The ZXCL devices include a current limit circuit which
restricts the maximum output current flow to typically
230mA. Practically the range of over-current should be
considered as minimum 160mA to maximum 800mA.
The device’s robust design means that an output short
circuit to any voltage between ground and VOUT can be
tolerated for an indefinite period.
Thermal Overload
Thermal overload protection is included on chip. When
the device junction temperature exceeds a minimum
125°C the device will shut down. The sense circuit will
re-activate the output as the device cools. It will then
cycle until the overload is removed. The thermal
overload protection will be activated when high load
currents or high input to output voltage differentials
cause excess dissipation in the device.
Start up delay
A small amount of hysteresis is provided on the Enable
pin to ensure clean switching. This feature can be used
to introduce a start up delay if required. Addition of a
simple RC network on the Enable pin provides this
function. The following diagram illustrates this circuit
connection. The equation provided enables calculation
of the delay period.
ISSUE 5 - NOVEMBER 2001
8
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
R
C
Figure 1 Circuit Connection
Td
T = RCIn V
V1.5
d(NOM)
IN
IN −
Calculation of start up delay as above
Figure 2 Start up delay (Td)
APPLICATIONS INFORMATION (Cont)
Power Dissipation
The maximum allowable power dissipation of the
device for normal operation (Pmax), is a function of the
package junction to ambient thermal resistance (θja),
maximum junction temperature (Tjmax), and ambient
temperature (Tamb), according to the expression:
Pmax = (Tjmax – Tamb) / θja
The maximum output current (Imax) at a given value of
Input voltage (VIN) and output voltage (VOUT) is then
given by
Imax = Pmax / (VIN - VOUT )
The value of θja is strongly dependent upon the type of
PC board used. Using the SC70 package it will range
from approximately 280 °C/W for a multi-layer board to
around 450°C/W for a single sided board. It will range
from 180°C/W to 300°C/W for the SOT23-5 package. To
avoid entering the thermal shutdown state, Tjmax
should be assumed to be 125°C and Imax less than the
over-current limit,(IOLIM). Power derating for the SC70
and SOT23-5 packages is shown in the following
graph.
Capacitor Selection and Regulator Stability
The device is designed to operate with all types of
output capacitor, including tantalum and low ESR
ceramic. For stability over the full operating range from
no load to maximum load, an output capacitor with a
minimum value of 1µF is recommended, although this
can be increased without limit to improve load
transient performance. Higher values of output
capacitor will also reduce output noise. Capacitors with
ESR less than 0.5Ωare recommended for best results.
An input capacitor of 1µF (ceramic or tantalum) is
recommended to filter supply noise at the device input
and will improve ripple rejection.
The input and output capacitors should be positioned
close to the device, and a ground plane board layout
should be used to minimise the effects of parasitic track
resistance.
Dropout Voltage
The output pass transistor is a large PMOS device,
which acts like a resistor when the regulator enters the
dropout region. The dropout voltage is therefore
proportional to output current as shown in the typical
characteristics.
Ground Current
The use of a PMOS device ensures a low value of
ground current under all conditions including dropout,
start-up and maximum load.
Power Supply Rejection and Load
Transient Response
Line and Load transient response graphs are shown in
the typical characteristics.
These show both the DC and dynamic shift in the
output voltage with step changes of input voltage and
load current, and how this is affected by the output
capacitor.
If improved transient response is required, then an
output capacitor with lower ESR value should be used.
Larger capacitors will reduce over/undershoot, but will
increase the settling time. Best results are obtained
using a ground plane layout to minimise board
parasitics.
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
9
-40-200 20406080100
0
100
200
300
400
500
SOT23
SC70
Derating Curve
Max Power Dissipation (mW)
Temperature (°C)
ISSUE 5 - NOVEMBER 2001
ISSUE 5 - NOVEMBER 2001
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
10
PACKAGE DIMENSIONS
SC70
DIM Millimetres
MIN MAX
A 1.00
A1 0.10
A2 0.70
b 0.15
C 0.08
D 2.00BSC
E 2.10BSC
E1 1.25BSC
e 0.65BSC
e1 1.30BSC
L 0.26 0.46
a°08
SOT23-5
DIM Millimetres
MIN MAX
A 0.90 1.45
A1 0.00 0.15
A2 0.90 1.3
b 0.35 0.50
C 0.09 0.20
D 2.80 3.00
E 2.60 3.00
E1 1.50 1.75
e 0.95 REF
e1 1.90 REF
L 0.10 0.60
a°010
ISSUE 5 - NOVEMBER 2001
Zetex plc
Fields New Road
Chadderton
Oldham, OL9 8NP
United Kingdom
Telephone (44) 161 622 4422
Fax: (44) 161 622 4420
Zetex GmbH
Streitfeldstraße 19
D-81673 München
Germany
Telefon: (49) 89 45 49 49 0
Fax: (49) 89 45 49 49 49
Zetex Inc
700 Veterans Memorial Hwy
Hauppauge, NY11788
USA
Telephone: (631) 360 2222
Fax: (631) 360 8222
Zetex (Asia) Ltd
3701-04 Metroplaza, Tower 1
Hing Fong Road
Kwai Fong, Hong Kong
China
Telephone: (852) 26100 611
Fax: (852) 24250 494
These offices are supported by agents and distributors in major countries world-wide.
This publication is issued to provide outline information only which (unless agreed by the Company in writing) may not be used, applied or
reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services
concerned. The Company reserves the right to alter without notice the specification, design, price or conditions of supply of any product or
service.
For the latest product information, log on to www.zetex.com
© Zetex plc 2001
ZXCL250 ZXCL260 ZXCL280
ZXCL300 ZXCL330 ZXCL400
11
ORDERING INFORMATION
DEVICE Output
Voltage
V
Package Partmarking
ZXCL250H5 2.5 SC70 L25A
ZXCL260H5 2.6 SC70 L26A
ZXCL280H5 2.8 SC70 L28A
ZXCL300H5 3.0 SC70 L30A
ZXCL330H5 3.3 SC70 L33A
ZXCL400H5 4.0 SC70 L40A
ZXCL1250H5 2.5 SC70 L25C
ZXCL1260H5 2.6 SC70 L26C
ZXCL1280H5 2.8 SC70 L28C
ZXCL1300H5 3.0 SC70 L30C
ZXCL1330H5 3.3 SC70 L33C
ZXCL1400H5 4.0 SC70 L40C
ZXCL250E5 2.5 SOT23-5 L25B
ZXCL260E5 2.6 SOT23-5 L26B
ZXCL280E5 2.8 SOT23-5 L28B
ZXCL300E5 3.0 SOT23-5 L30B
ZXCL330E5 3.3 SOT23-5 L33B
ZXCL400E5 4.0 SOT23-5 L40B
