Ver 1.7
BCT2019
Low Power, Low Dropout, RF-Linear Regulators
GENERAL DESCRIPTION
FEATURES
The BCT2019 series low-power, low-noise,
low-dropout, CMOS linear voltage regulators
operate from a 2.5V to 5.5V input voltage. They
are the perfect choice for low voltage, low power
applications. A low ground current makes this part
attractive for battery operated power systems. The
BCT2019 series also offer ultra-low dropout
voltage to prolong battery life in portable
electronics. Systems requiring a quiet voltage
sources, such as RF applications, will benefit from
the BCT2019 series ultra-low output noise
(30uVRMS) and high PSRR. An external noise
bypass capacitor connected to the device’s BP pin
can further reduce the noise level.
The output voltage is preset to voltages in the
range of 1.2V to 5.0V. Other features include a
10nA logic-controlled shutdown mode, foldback
current limit and thermal shutdown protection.
The BCT2019 is available in Green SOT-23-5 and
SC70-5 packages. It operates over an ambient
temperature range of -40°C to +85°C.
www.broadchip.com
Low Output Noise
Low Dropout Voltage
Thermal-Overload Protection
Output Current Limit
High PSRR(74dB at 1kHz)
10nA Logic-Controlled Shutdown
Available in Multiple output Voltage Versions
Fixed Outputs of 1.2V, 1.5V, 1.8V, 2.5V, 2.8V,
2.85V, 3.0V and 3.3V
Adjustable Output from 1.2V to 5.0V
-40°C to 85°C Operating Temperature Range
Available in Green SC70-5 and SOT-23-5
Packages
APPLICATIONS
Cellular Telephones
Cordless Telephones
PCMCIA Cards
Modems
MP3 Player
Hand-Held Instruments
Portable/Battery-Powered Equipment
1
Ver 1.7
ORDERING INFORMATION
Order Number
VOUT(V)
Package Type
Temperature Range
Marking
QTY/Reel
BCT2019EUKV12-TR
1.2
SOT23-5
-40°C to +85°C
F2ZZ
3000
BCT2019EUKV15-TR
1.5
SOT23-5
-40°C to +85°C
F5ZZ
3000
BCT2019EUKV18-TR
1.8
SOT23-5
-40°C to +85°C
F8ZZ
3000
BCT2019EUKV25-TR
2.5
SOT23-5
-40°C to +85°C
F5ZZ
BCT2019EUKV28-TR
2.8
SOT23-5
-40°C to +85°C
F8ZZ
BCT2019EUKV29-TR
2.85
SOT23-5
-40°C to +85°C
F9ZZ
3000
BCT2019EUKV30-TR
3
SOT23-5
-40°C to +85°C
F0ZZ
3000
BCT2019EUKV33-TR
3.3
SOT23-5
-40°C to +85°C
F3ZZ
3000
BCT2019EUKVAJ-TR
ADJ
SOT23-5
-40°C to +85°C
FJZZ
3000
BCT2019EXKV12-TR
1.2
SC70-5
-40°C to +85°C
LK12
3000
BCT2019EXKV15-TR
1.5
SC70-5
-40°C to +85°C
LK15
3000
BCT2019EXKV18-TR
1.8
SC70-5
-40°C to +85°C
LK18
3000
BCT2019EXKV25-TR
2.5
SC70-5
-40°C to +85°C
LK25
3000
BCT2019EXKV28-TR
2.8
SC70-5
-40°C to +85°C
LK28
3000
BCT2019EXKV29-TR
2.85
SC70-5
-40°C to +85°C
LK285
3000
BCT2019EXKV30-TR
3
SC70-5
-40°C to +85°C
LK30
3000
BCT2019EXKV33-TR
3.3
SC70-5
-40°C to +85°C
LK33
3000
BCT2019EXKVAJ-TR
ADJ
SC70-5
-40°C to +85°C
LKAJ
3000
www.broadchip.com
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2
3000
3000
Ver 1.7
ABSOLUTE MAXIMUM RATINGS
CAUTION
IN to GND.......................................................-0.3V to 6V
This integrated circuit can be damaged by ESD if you don’t
EN to GND……………....................................-0.3V to VIN
pay attention to ESD protection. Broadchip recommends
OUT, BP/FB to GND...........................-0.3V to (VIN+0.3V)
that all integrated circuits be handled with appropriate
Output Short-Circuit Duration.................................Infinite
precautions. Failure to observe proper handling and
Power Dissipation, PD@TA=25℃
installation procedures can cause damage. ESD damage
SOT-23-5..................................................................0.4W
can range from subtle performance degradation to
SC70-5.....................................................................0.3W
complete device failure. Precision integrated circuits may
Package Thermal Resistance
be more susceptible to damage because very small
SOT-23-5, θJA......................................................260℃/W
parametric changes could cause the device not to meet its
SC70-5, θJA..........................................................330℃/W
published specifications.
Junction Temperature..............................................150℃
Operating Temperature Range.................-40℃ to +85℃
Broadchip reserves the right to make any change in circuit
Storage Temperature Range....................-65℃ to 150℃
design, specification or other related things if necessary
Lead Temperature (Soldering, 10 sec).....................260℃
without notice at any time. Please contact Broadchip sales
ESD Susceptibility
office to get the latest datasheet.
HBM.....................................................................2000V
MM.........................................................................200V
NOTE:
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 rating conditions for extended periods may affect device
reliability.
www.broadchip.com
3
Ver 1.7
PIN CONFIGURATION
SOT23-5/SC70-5
TOP VIEW
1
GND
2
EN
3
5
OUT
4
BP/FB
MARKING
IN
PIN DESCRIPTION
PIN
NAME
1
IN
2
GND
3
EN
Shutdown Input. A logic low reduces the supply current to 10nA. Connect to IN
for normal operation.
BP
Reference-Noise Bypass (fixed voltage version only). Bypass with a low-leakage
0.01uF ceramic capacitor for reduced noise at the output.
FB
Adjustable Voltage Version Only. This is used to set the output voltage of the
device.
4
5
OUT
FUNCTION
Regulator Input. Supply voltage can range from 2.5V to 5.5V. Bypass with a 1uF
capacitor to GND.
Ground.
Regulator Output.
www.broadchip.com
4
Ver 1.7
ELECTRICAL CHARACTERISTICS
(VIN= VOUT(NOMINAL)+0.5V(1), Full = -40℃ to +85℃, unless otherwise specified.)
PARAMETER
SYM
Input Voltage
CONDITIONS
VIN
(1)
Output Voltage Accuracy
IOUT=0.1mA
Maximum Output Current
Current Limit
ILIM
Ground Pin Current
IQ
Dropout Voltage(2)
Line Regulation
Load Regulation
Output Voltage Noise
Power Supply Rejection Ratio
SHUTDWON
ΔVLNR
ΔVLDR
en
MIN
TYP
MAX UNITS
2.5
5.5
V
-2.5
2.5
%
SOT-23-5
300
VOUT=1.2V,1.5V,1.8V, SC70-5
150
VOUT>2V, SC70-5
250
mA
800
No load, EN=2V
100
mA
200
IOUT=1mA
0.9
IOUT=300mA
270
400
VIN=2.5V or (VOUT+0.5V) to
5.5V, IOUT=1mA
0.02
0.05
IOUT=0.1mA to 300mA,
COUT=1uF, VOUT>2V
0.002 0.005
IOUT=0.1mA to 300mA,
COUT=1uF, VOUT≤2V
0.004 0.008
uA
mV
%/V
%/mA
f=10Hz to 100kHz,
CBP=0.01uF, COUT=10uF
30
f=
CBP=0.1uF,
PSRR ILOAD=50mA, COUT=1uF, 217Hz
VIN=VOUT+1V
f=1kHz
uVRMS
77
dB
74
(3)
EN Input Threshold
VIH
VIL
VIN=2.5V to 5.5V,
VEN=-0.3V to VIN
1.5
0.3
EN Input Bias Current
IB(SHDN) EN=0V or EN=5.5V
0.01
Shutdown Supply Current
IQ(SHDN) EN=0.4V
0.01
uA
30
us
TSHDN
150
°C
ΔTSHDN
15
°C
CBP=0.01uF, COUT=1uF,
No Load
Shutdown Exit Delay(4)
1
V
uA
THERMAL PROTECTION
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
NOTES:
1. VIN = VOUT (NOMINAL) + 0.5V or 2.5V, whichever is greater.
2. The dropout voltage is defined as VIN - VOUT, when VOUT is 100mV below the value of VOUT for VIN = VOUT + 0.5V.
(Only applicable for VOUT = +2.5V to +5.0V.)
3. VEN = -0.3V to VIN
4. Time needed for VOUT to reach 90% of final value.
www.broadchip.com
5
Ver 1.7
TYPICAL APPLICATION CIRCUIT
CBP(nF)
Shutdown Exit Delay(us)
VOUT=2.8V, VIN=3.3V, EN=0V to 2V
ILOAD=50mA ILOAD=150mA ILOAD=300mA
PSRR(dB) at 217Hz
VOUT=2.8V, VIN=VOUT+1V
ILOAD=50mA ILOAD=150mA ILOAD=300mA
None
21.5
21.5
21
71.1
64.4
55
0.001
21.5
21.5
22
71.1
64.6
55.1
0.01
22
22.5
22.5
71.6
64.7
55.2
0.1
22.5
23
23
71.7
64.8
55.4
1
25
27
28.5
72.1
65.2
55.9
10
30
35
39
74.3
68.8
59.6
100
265
280
300
77
73.7
63.1
www.broadchip.com
6
Ver 1.7
TYPICAL APPLICATION CIRCUIT
Standard 1% Resistor Values for Common Output Voltages of Adjustable Voltage Version
VOUT (V)
R1 (kΩ)
R2 (kΩ)
1.2
0
63.4
1.5
10.5
42.2
1.8
34
63.4
2.8
84.5
63.4
3.0
63.4
42.2
3.3
73.2
42.2
3.6
84.5
42.2
4.2
105
42.2
NOTE: VOUT = (R1 + R2)/ R2 × 1.207
www.broadchip.com
7
Ver 1.7
APPLICATION NOTE
When LDO is used in handheld products, attention must be paid to voltage spikes which could damage
BCT2019. In such applications, voltage spikes will be generated at charger interface and VBUS pin of
USB interface when charger adapters and USB equipments are hot-plugged. Besides this, handheld
products will be tested on the production line without battery. Test engineer will apply power from the
connector pin which connects with positive pole of the battery. When external power supply is turned on
suddenly, the voltage spikes will be generated at the battery connector. The voltage spikes will be very
high, and it always exceeds the absolute maximum input voltage (6.0V) of LDO. In order to get robust
design, design engineer needs to clear up this voltage spike. Zener diode is a cheap and effective
solution to eliminate such voltage spike. For example, BZM55B5V6 is a 5.6V small package Zener diode
which can be used to remove voltage spikes in cell phone designs. The schematic is shown below.
Bypass Capacitor and Low Noise
Connecting a 22nF between the BP pin and GND pin significantly reduces noise on the regulator output, it
is critical that the capacitor connection between the BP pin and GND pin be direct and PCB traces should
be as short as possible. There is a relationship between the bypass capacitor value and the LDO
regulator turn on time. DC leakage on this pin can affect the LDO regulator output noise and voltage
regulation performance.
Enable Function
The BCT2019 features an LDO regulator en-able/disable function. To assure the LDO regulator will
switch on; the EN turn on control level must be greater than 1.2 volts. The LDO regulator will go into the
shutdown mode when the voltage on the EN pin falls below 0.4 volts. For to protect the system, the
BCT2019 have a quick discharge function. If the enable function is not needed in a specific application, it
may be tied to VIN to keep the LDO regulator in a continuously on state.
www.broadchip.com
8
Ver 1.7
Programming the BCT2019 Adjustable LDO regulator
The output voltage of the BCT2019 adjustable regulator is programmed using an external resistor divider
as show in Figure as below. The output voltage is calculated using equation as below:
R1
VOUT VREF 1
R2
Where:
VREF=1.207V typ (the internal reference voltage)
Resistors R1 and R2 should be chosen for approximately 50uA divider current. Lower value resistors can
be used for improved noise performance, but the solution consumes more power. Higher resistor values
should be avoided as leakage current into/out of FB across R1/R2 creates an offset voltage that artificially
increases/decreases the feedback voltage and thus erroneously decrease/increases VOUT.
Thermal Considerations
Thermal protection limits power dissipation in BCT2019. When the operation junction temperature
exceeds 150°C, the OTP circuit starts the thermal shutdown function turn the pass element off. The pass
element turns on again after the junction temperature cools by 15°C.
For continue operation, do not exceed absolute maximum operation junction temperature 125°C. The
power dissipation definition in device is:
PD = (VIN−VOUT) ×IOUT + VIN×IQ
The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate
of surroundings airflow and temperature difference between junction to ambient. The maximum power
dissipation can be calculated by following formula:
PD(MAX) = ( TJ(MAX) − TA ) /θJA
Where TJ(MAX) is the maximum operation junction temperature 125°C, TA is the ambient temperature
and the θJA is the junction to ambient thermal resistance. For recommended operating conditions
specification of BCT2019, where TJ(MAX) is the maximum junction temperature of the die (125°C) and TA
is the maximum ambient temperature. The junction to ambient thermal resistance (θ JA is layout
dependent) for SOT-23-5 package is 250°C/W, SC-70-5 package is 333°C/W, on standard JEDEC 51-3
thermal test board. The maximum power dissipation at TA= 25°C can be calculated by following formula:
PD(MAX) = (125°C−25°C)/333 = 300mW (SC-70-5)
www.broadchip.com
9
Ver 1.7
PD(MAX) = (125°C−25°C)/250 = 400mW (SOT-23-5)
The maximum power dissipation depends on operating ambient temperature for fixed TJ(MAX) and
thermal resistance θJA. It is also useful to calculate the junction of temperature of the BCT2019 under a
set of specific conditions. In this example let the Input voltage VIN=3.3V, the output current Io=300mA and
the case temperature TA=40°C measured by a thermal couple during operation. The power dissipation for
the Vo=2.8V version of the BCT2019 can be calculated as:
PD = (3.3V−2.8V) ×300mA+3.6V×100uA
=150mW
And the junction temperature, TJ, can be calculated as follows:
TJ=TA+PD×θJA=40°C+0.15W×250°C/W
=40°C+37.5°C=77.5°C