TB9001FNG
TOSHIBA BiCMOS INTEGRATED CIRCUIT SILICON MONOLITHIC FOR AUTOMOTIVE USE
TB9001FNG
5 V Voltage Regulator with Watchdog Timer
The TB9001FNG is specially designed for microcomputer systems.
The IC features low standby current, oscillator function for CPU
sub-clock and various system reset functions.
With external power transistor, TB9001FNG can supply high output
current. As a protective feature, current limiter function is incorporated.
For system reset includes low voltage reset, power-on reset, and
watchdog timer functions.
SSOP20-P-225-0.65A
Weight : 0.1g(typ.)
FEATURES
•
•
•
•
•
•
Accurate output
Low current consumption
Reset functions
Current limiter
Operating temperature
Small SMD package
: 5.0V ± 0.15V
: 95µA (VIN=12V, Ta=25°C) at 5V output + reset timer + 32kHz sub-clock
: Low voltage reset / power on reset / watchdog timer
: Adjustable with external resistor
: -40~125°C
: SSOP-20pin
About solderability, the following conditions were confirmed.
Solderability
(1) Use of Sn-37Pb solder Bath
solder bath temperature = 230°C
dipping time = 5 seconds
the number of times = once
use of R-type flux
(2) Use of Sn-3.0Ag-0.5Cu solder Bath
solder bath temperature = 245°C
dipping time = 5 seconds
the number of times = once
use of R-type flux
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TB9001FNG
BLOCK DIAGRAM AND PIN LAYOUT
TR
TC
NC
WS
SCK
NC
RESET
NC
CK
GND
20
19
18
17
16
15
14
13
12
9
Output
32kHz OSC
LOGIC
Band Gap
Power ON
Reset
Current Limiter
Constant
Voltage
VIN
NC
NC
VS
OUT
COMP
VCC
NC
TADJ-L TADJ-H
Note:
Some of the functional blocks, circuits, or constants in the block diagram are omitted or simplified to clarify
the descriptions of the relevant features.
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10
1
2
3
4
5
6
7
8
11
TB9001FNG
PIN DESCRIPTION
PIN No.
1
SYMBOL
VIN
DESCRIPTION
Power supply input pin. It contains current limiter and startup circuit.
Detection pin for the Vcc current limiter. This pin monitors any voltage drop occurring in the
external resistor Rs between pins VIN and Vs, and the current limiter is actuated when the
4
Vs
voltage drop exceeds 0.7 V.
Ex.) When the current limiter need to be actuated at a load current of 250mA,
Rs
＝
0.7 V / 250 mA
＝
2.8
Ω
This pin is used to connect the base of an external PNP transistor. The output voltage is
5
OUT
controlled by an internal op-amp to keep it stable at 5 V. Since the recommended current
of Iout is 5 mA, an output current of 300mA can be run if the HFE of the external transistor is
60 or more.
6
7
COMP
Vcc
Phase compensating pin for Vcc. Connect a phase compensating capacitor between pin Vcc
and this pin.
Voltage detection pin for the 5 V constant-voltage power supply, Vcc. This pin also supplies
power to the reset timer circuit.
Time setup pins for the reset and watchdog timers. For a 32 kHz sub-clock, the time is set
9
TADJ-L
by combinations of TADJ-L and TADJ-H.
( These pins must be connected to Vcc or 0V because of logic input.)
TADJ-H = Vcc , TADJ-L = Vcc : TPOR = 50ms , TWD = 50ms , TRST = 5ms
TADJ-H = Vcc , TADJ-L = 0V : TPOR = 200ms , TWD = 100ms , TRST = 10ms
10
11
12
TADJ-H
GND
CK
TADJ-H = 0V , TADJ-L = Vcc : TPOR = 50ms , TWD = 25ms , TRST = 2.5ms
TADJ-H = 0V , TADJ-L = 0V : TPOR = 100ms , TWD = 50ms , TRST = 5ms
Grounded
Clock input pin for the watchdog timer. This pin detects rising edge of the input signal and
does not require external coupling capacitor.
Reset output pin for power on reset and watchdog timer.
14
______
RESET
SCK
WS
TC
TR
NC
Generates a reset signal that is determined by sub-clock and TADJ pins.
If no clock is fed to the CK input, this pin generates a reset pulse intermittently.
This is an N-MOS drain output with 100 kΩ pull-up resistor.
16
17
19
20
2 , 3 , 8 , 13 ,
15 , 18
Sub-clock output pin for CPU.
Watchdog timer function ON / OFF control pin. Set to "Low" for active mode and "High" for
Inactive mode.
Time setup pin for sub-clock. Connect capacitor CT to GND.
The time is set using the internal constant current from TR pin.
Time setup pin for sub-clock. Connect resistor RT between TC pin and TR pin.
Not connected. ( Electrically, these pins are completely open. )
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TB9001FNG
Functional Description
· Sub-Clock Oscillation Circuit
This IC has a built -in sub-clock function the basic circuit configuration of which comprises a CR charge-discharge
circuit and a detection circuit for oscillator abnormalities. The sub-clock is also used as the source oscillation frequency
for the timer functions: power on reset, watchdog, and reset.
Basic Operation
The resistor RT which sets the charge-and-discharge current, is connected between TC and TR pins, and the capacitor
CT is connected between TC and GND pins. The TC pin is repeatedly charged and discharged between VCC04 and
VCC06. If TC pin or TR pin is shorted to Vcc or GND, the RESET signal goes to LOW.
External Resistor and Capacitor
VCC06 : Vcc x 0.6
VCC04 : Vcc x 0.4
fosc ( Hz ) = 1 / (( t1 + t2 ) x 2 )
t1 = RT x CT x ln( VCC06 / VCC04 )
t2 = Delay time of internal circuit
≈
1µs
[ Example ] CT = 75pF , RT = 480kΩ
t1 = 480 kΩ x 75 pF x ln( 3 V / 2 V ) = 14.6 µs
fosc = 1 / (( 14.6 µs + 1 µs ) x 2 )
≈
32.05 kHz
t1
t2
VCC
t1
VCC06
VCC04
t2
GND
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2007-03-19
TB9001FNG
TIMING CHART
5V
V
TH
V
TH-L
（V
TH
－ΔV
TH
）
V
TH
V
TH-L
（V
TH
－ΔV
TH
）
Vcc
0V
CK
0V
RESET
0V
T
RST
T
WD
Td
T
POR
T
WD
Td
WS
0V
T
POR
T
WD
SCK
0V
Note1:
Note2:
See ELECTRICAL CHARACTERISTICS about symbols in timing charts.
Timing charts may be simplified to clarify the descriptions of features and operations.
ABSOLUTE MAXIMUM RATING (Ta=25°C)
CHARACTERISTIC
SYMBOL
V
IN
1
Input Voltage
V
IN
2
V
IN
3
I
OUT
1
Output Current
I
OUT
2
I
OUT
3
Output Voltage
Operating Temperature
Storage Temperature
Note:
V
OUT
1
V
OUT
2
T
opr
T
stg
PIN
V
IN
,V
S
V
CC
CK,WS,TC,
TADJ-H,TADJ-L
OUT
RESET
SCK
OUT
RESET,SCK
-
-
------------------
------------------
RATING
45 (1s)
6.0
V
CC
5
5
±1
45 (1s)
V
CC
−40~125
−55~150
UNIT
V
mA
V
°C
°C
The absolute maximum ratings of a semiconductor device are a set of specified parameter values that must
not be exceeded during operation, even for an instant.
If any of these levels is exceeded during operation, the electrical characteristics may be irreparably altered
and the reliability and lifetime of the device can no longer be guaranteed, possibly causing damage to any
other equipment with which it is used. Applications using the device should be designed so that the absolute
maximum ratings will never be exceeded in any operating conditions.
Ensuring that the parameter values remain within these specified ranges during device operation will help to
ensure that the integrity of the device is not compromised.
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