TC1188
TC1189
MAX8863/64 Pin-Compatible, Low-Dropout, 120mA Linear Regulators
FEATURES
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Low Cost
Pin-Compatible with MAX8863/8864
Stable with Any Type of Capacitors
Low, 55mV Dropout Voltage @ 50mA I
OUT
Low, 50
µ
A Operating Supply Current (Even in
Dropout)
140
µ
sec (typ.) Turn-On Response Time from
SHDN
Low, 350
µ
V
RMS
Output Noise
Miniature External Components
Thermal Overload Protection
Output Current Limit
Low-Power Shutdown Mode
GENERAL DESCRIPTION
Delivering up to 120mA, the TC1188 and TC1189 are
fixed output, low-dropout linear regulators that operate from
a +2.5V to +6.0V input range. The 50µA supply current
remains independent of load, making these devices ideal for
battery-operated portable equipment.
The output of the TC1188/1189 is preset at 3.15V,
2.84V, 2.80V or 1.80V. (Other output voltage options are
available — contact TelCom Semiconductor for more infor-
mation.) In addition to low-power shutdown, short-circuit
protection, and thermal shutdown protection, the TC1189
includes an auto-discharge function that actively discharges
the output voltage to ground when the device is in shutdown
mode. Both devices are pin-compatible with the Maxim
MAX8863/8864 LDOs and are available in SOT-23-5 pack-
ages.
APPLICATIONS
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Cordless, PCS, and Cellular Telephones
PCMCIA Cards
Modems
Hand-Held Instruments
Palmtop Computers
Electronic Planners
ORDERING INFORMATION
Part No.
TC1188xECT
TC1189xECT
Package
SOT-23-5
SOT-23-5
Temp. Range
–40°C to +85°C
–40°C to +85°C
TYPICAL APPLICATION
NOTES:
1.The "X" denotes a suffix for output voltage - see table below
2. SOT-23A-5 is equivalent to the EIAJ (SC-74A)
3.Other output voltages available. Please contact TelCom
Semiconductor for details
Suffix
IN
OUT
Output
Voltage
Output Voltage
1.80
2.80
2.84
3.15
C
IN
1µF
Battery
TC1188
TC1189
SHDN
C
OUT
1µF
Q
R
S
T
PIN CONFIGURATION
GND
GND
SOT-23A-5
SHDN
1
TC1188
TC1189
5
GND
GND
2
IN
3
4
OUT
TC1188/1189-2 4/18/00
TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices.
MAX8863/64 Pin-Compatible Low-Dropout,
120mA Linear Regulators
TC1188
TC1189
ABSOLUTE MAXIMUM RATINGS*
Input Voltage .............................................................. 6.5V
Output Short-Circuit Duration ................................. Infinite
SET to GND .............................................. –0.3V to +6.5V
SHDN to GND ........................................... –6.5V to +6.5V
SHDN to IN ............................................... –6.5V to +0.3V
Output Voltage .............................. (–0.3V) to (V
IN
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
SOT-23-5 (derate 7.1 mW/°C above +70°C)
.......................................................................571 mW
Operating Temperature Range .................. –40°C to 85°C
Storage Temperature Range ................. –65°C to +160°C
Lead Temperature (Soldering, 10 sec) ................. +300°C
* Stresses above 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 above
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.
ELECTRICAL CHARACTERISTICS:
(V
IN
= +3.6V, GND = 0V, T
A
= T
MIN
to T
MAX,
unless otherwise specified.
Typical values are at T
A
= +25°C.) (Note 1)
Symbol
V
IN
V
OUT
Parameter
Input Voltage (Note 2)
Output Voltage
Test Conditions
V
OUT
≥
2.5V
V
OUT
= 1.8V
0mA
≤
I
OUT
≤
50mA
Min
V
OUT
+ .5V
2.7
3.05
2.75
2.70
1.745
120
—
—
—
—
—
–0.10
—
—
—
—
—
Typ
—
—
3.15
2.84
2.80
1.80
—
280
50
1.1
55
110
.001
—
0.01
350
220
10
Max
6.0
6.0
3.25
2.93
2.88
1.85
—
—
90
—
120
240
0.10
—
0.040
—
—
—
Unit
V
V
T
S
R
Q
I
OUT
I
LIM
I
IN
Maximum Output Current
Current Limit (Note 3)
Input Current
Dropout Voltage (Note 4)
∆V
LNR
∆V
LDR
Line Regulation
Load Regulation
Output Voltage Noise
Wake Up Time
(from Shutdown Mode)
Settling Time
(from Shutdown Mode)
t
WK
t
S
I
OUT
= 0
I
OUT
= 1mA
I
OUT
= 50mA
I
OUT
= 100mA
V
IN
= V
OUT
+ 0.5V to 6.0V
I
OUT
= 1mA
I
OUT
= 0mA to 50mA
10Hz to 1MHz
C
OUT
= 1µF
C
OUT
= 100µF
V
IN
= 3.6V
C
IN
= 1µF, C
OUT
= 1µF
I
L
= 30mA, (See Fig. 1)
V
IN
= 3.6V
C
IN
= 1µF, C
OUT
= 1µF
I
L
= 30mA, (See Fig. 1)
mA
mA
µA
mV
%/V
%/mA
µV
RMS
µsec
—
140
—
µsec
Shutdown
V
IH
V
IL
I
SHDN
I
QSHDN
SHDN Input Threshold
SHDN Input Bias Current
Shutdown Supply Current
V
SHDN
= V
IN
V
OUT
= 0V
T
A
= +25°C
T
A
= T
MAX
T
A
= +25°C
T
A
= T
MAX
Shutdown to Output
C
OUT
= 1µF, no load
Discharge Delay (TC1189)
To 10% of V
OUT
Thermal Protection
T
SHDN
Thermal Shutdown Temperature
∆T
SHDN
Thermal Shutdown Hysteresis
TC1188/1189-2 4/18/00
2.0
—
—
—
—
—
—
—
—
0
50
.002
0.02
1
—
0.4
100
—
1
—
—
V
nA
µA
msec
—
—
170
20
—
—
°C
°C
2
MAX8863/64 Pin-Compatible Low-Dropout,
120mA Linear Regulators
TC1188
TC1189
NOTES:
1.Limits are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed through correlation using
Statistical Quality Control (SQC) Methods.
2.Guaranteed by line regulation test.
3.Not tested. For design purposes, the current limit should be considered 150mA minimum to 410mA maximum.
4.The dropout voltage is defined as (V
IN
– V
OUT
) when V
OUT
is 100mV below the value of V
OUT
for V
IN
= V
OUT
+2V.
PIN DESCRIPTION
Pin Number
1
Name
SHDN
Description
Active-Low Shutdown Input. A logic low reduces the supply current to 0.1nA. On
the TC1189, a logic low also causes the output voltage to discharge to GND.
Connect to IN for normal operation.
Ground. This pin also functions as a heatsink. Solder to large pads or the circuit
board ground plane to maximize thermal dissipation.
Regulator Input. Supply voltage can range from +2.5V (+2.7V for V
OUT
= 1.8V) to
+6.0V. Bypass with 1µF to GND (see
Capacitor Selection and Regulator Stability
).
Regulator Output. Sources up to 120mA. Bypass with a 1µF, <1
Ω
typical ESR
capacitor to GND.
Connect to GND.
2
3
4
5
GND
IN
OUT
GND
DETAILED DESCRIPTION
The TC1188/1189 are fixed output, low-dropout, low-
quiescent current linear regulators designed specifically for
portable, battery-operated equipment such as cellular
phones, cordless phones, and modems. A 1.20V reference,
error amplifier, MOSFET driver, P-channel pass transistor,
comparator, and internal feedback voltage divider comprise
the TC1188/1189 (see Figure 2).
The bandgap reference is connected to the error
amplifier's inverting input. The error amplifier then compares
the reference with the selected feedback voltage and ampli-
fies the difference. The MOSFET driver, reading the error
signal, applies the correct drive to the P-channel pass
transistor. If the feedback voltage is lower than the refer-
ence, the pass-transistor is pulled lower to allow more
current through, and to increase the output voltage. Con-
versely, if the feedback voltage is higher than the reference,
the pass-transistor is pulled up, which allows less current
through to the output.
V
IH
SHDN
V
IL
98%
V
OUT
2%
t
WK
t
S
Figure 1: Wake Up Response Time
The total turn on response is defined as the
Settling Time
(t
S
),
see Figure 1.
Settling Time
(inclusive with t
WK)
is defined
as the condition when the output is within 2% of its fully enabled
value (140µsec typical) when released from shutdown. The
settling time of the output voltage is dependent on load
conditions and output capacitance on V
OUT
(RC response).
Turn On Response
The turn on response is defined as two separate re-
sponse categories,
Wake Up Time (t
WK
)
and
Settling Time
(t
S
).
The TC1188/89 have a fast Wake Up Time (10µsec
typical) when released from shutdown. See Figure 1 for the
Wake Up Time
designated as
t
WK
. The
Wake Up Time
is
defined as the time it takes for the output to rise to 2% of the
V
OUT
value after being released from shutdown.
Internal P-Channel Pass Transistor
Featuring a 1.1Ω P-channel MOSFET pass transistor,
the TC1188/1189 offers longer battery life than similar
designs using PNP pass transistors, which waste current in
dropout when the pass transistor saturates. PNP-based
regulators also use high base-drive currents under large
loads. The P-channel MOSFET, however, does not require
a base drive current, which reduces quiescent current. The
TC1188/1189 use only 50µA of quiescent current.
TC1188/1189-2 4/18/00
3
MAX8863/64 Pin-Compatible Low-Dropout,
120mA Linear Regulators
TC1188
TC1189
IN
SHDN
SHUTDOWN
LOGIC
ERROR
AMP
–
+
MOS DRIVER
WITH I
LIMIT
P
OUT
N
(TC1189 Only)
THERMAL
SENSOR
GND
1.2V
REF
GND
Figure 2. Functional Block Diagram
Shutdown
Low input on SHDN shuts down the TC1188/1189 by
turning off the pass transistor, control circuit, reference, and
all biases. This reduces the supply current to 0.1nA, typical.
For normal operation, connect SHDN to IN. When theTC1189
is placed in shutdown mode, the output voltage is actively
discharged to ground.
This feature is designed to protect the TC1188/1189
during thermal events. High load currents and high input-
output differential voltages may cause a momentary over-
shoot of 2% to 8% for 200msec when the load is removed.
This can be avoided by raising the minimum load current from
0µA (+125°C) to 100µA (+150°C). The maximum junction
temperature rating of +150°C should not be exceeded for
continuous operation.
Current Limit
The current limiter on the TC1188/1189 monitors and
controls the pass transistor’s gate voltage. It estimates the
output current, limiting it to 280mA. The current limit should
be considered 150mA (min) to 410mA (max) for design
purposes. The output can be shorted to ground indefinitely
without damaging the device.
Operating Region and Power Dissipation
The TC1188/1189’s maximum power dissipation de-
pends on the thermal resistance of the case and circuit board,
the rate of air flow, and the temperature difference between
the die junction and ambient air. The devices’ power dissipa-
tion is P = I
OUT
(V
IN
– V
OUT
); resulting maximum power
dissipation is :
P
MAX
= (T
J
– T
A
)/Θ
JA
where (T
J
– T
A
) is the temperature difference between
the devices’ die junction and the surrounding air, and
Θ
JA
is
the thermal resistance of the chosen package to the sur-
rounding air.
The devices’ GND pin provides an electrical connection
to ground and channels heat away. The GND pin should be
connected to ground with a large pad or ground plane.
Thermal Overload Protection
The TC1188/1189 features thermal overload protec-
tion, which limits total power dissipation. The thermal sen-
sor signals the shutdown logic to turn off the pass transistor
when the junction temperature exceeds T
J
= +170°C. This
allows the IC’s junction temperature to cool by 20°C before
the thermal sensor turns the pass transistor back on. This
results in a pulsed output during continuous thermal over-
load conditions.
TC1188/1189-2 4/18/00
4
MAX8863/64 Pin-Compatible Low-Dropout,
120mA Linear Regulators
TC1188
TC1189
APPLICATIONS INFORMATION
Capacitor Selection and Regulator Stability
A 1µF capacitor on the input, and a 1µF capacitor on the
output should generally be used on the TC1188/1189. For
better supply-noise rejection and transient response, larger
input capacitor values and lower ESR should be used. If the
device is several inches from the power source or if large,
fast transients are expected, a higher-value input capacitor
(10µF) may be required.
Using large output capacitors may improve load-tran-
sient response, stability, and power-supply rejection. A
minimum of 1µF is recommended for stable operation over
the full temperature range with load currents up to 120mA.
Noise
During normal operation, the TC1188/1189 have low
(350µV
RMS
) output noise. The ADC’s power-supply rejec-
tion specifications should be considered for applications
that include analog-to-digital converters of greater than 12
bits.
Power-Supply Rejection and Operation from
Sources Other than Batteries
Power-supply rejection for the TC1188/1189 is 62dB at
low frequencies, rolling off above 300Hz. Power supply
noise rejection is primarily controlled by the output capacitor
at frequencies of more than 20KHz.
Supply noise rejection and transient response can be
improved when operating from sources other than batteries
by increasing the values of the input and output capacitors,
and using passive filtering techniques.
Load Transient Considerations
With the TC1188/1189, typical overshoot for step
changes in the load current from 0mA to 50mA is 12 mV. To
lessen transient spikes, increase the output capacitor’s
value, and decrease its ESR.
Input-Output (Dropout) Voltage
A regulator’s dropout voltage determines the lowest
usable supply voltage. This determines the useful end-of-
life battery voltage for battery-powered systems. Since the
TC1188/1189 uses a P-channel MOSFET pass transistor,
the devices’ dropout voltage is a function of R
DS(ON)
multi-
plied by the load current.
TC1188/1189-2 4/18/00
5
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