tca5600 Freescale Semiconductor, Inc, tca5600 Datasheet - Page 10

• Manufacturer Part Number: tca5600
• Description: Universal Microprocessor Power Supply/controllers
• Manufacturer: Freescale Semiconductor, Inc

Programmable Voltage Regulator
voltage divider R4, R5 for a nominal output voltage of 6.0 V
V out2
Current limitation and thermal shutdown capability are
standard features of this regulator. The voltage drop
the feedback signal to control the dc/dc converter
(see Figure 13).
Control Inputs INH1, INH2
controllable through the TTL, MOS compatible inhibit inputs
INH1 and INH2 where the latter is a three–level detector
(Logic “0”, High Impedance “Z”, Logic “1”). Both inputs are
set–up to provide the following truth table:
Figure 16 represents a typical timing diagram for an E 2 PROM
programming sequence in a microprocessor based system.
The High “Z” state enables the dc/dc converter to ramp during
t 3 to the voltage V 9 at Pin 9 to a high level before the write
cycle takes place in the memory.
INT:
ON:
OFF:
V CC2
V out2
V (Pin 9 – Pin 8) across the series pass transistor generates
5.0V
INH1
INH2
Figure 16. Typical E 2 PROM Programming Sequence
“1”
“0”
10
This series voltage regulator is programmable by the
The dc/dc converter and/or the regulator V out2 are remote
“1”
”0”
V 9
– V F
Mode
30 V.
Intermittent operation of the converter means that the
converter operates only if V CC2 <V out2 .
The converter loads the storage capacitor C2 to its full
charge (V 9 = 33 V), allowing fast response time of the
regulator V out2 when addressed by the control software.
High impedance (internal resistor 10 k to ground)
1
2
3
4
5
6
V 9 max
High “Z”
Figure 15. INH1, INH2 TruthTable
[R5 = 10 k, V ref nom = 2.5 V]
R4 =
t 3
INH1
0
0
0
1
1
1
t 4
(V out2 – V ref nom ) R5
(not to scale)
V 9 int
High “Z”
High “Z”
INH2
Programming
Voltage VPP
0
1
0
1
V ref nom
V out2
V out2
V out2
5.0 V
5.0 V
OFF
OFF
DC/DC
INT
INT
INT
INT
ON
ON
TCA5600 TCF5600
(7)
t
Microprocessor Supply Regulator
5.0 V supply exhibiting low voltage drop is obtained to power
microprocessor systems and auxiliary circuits. Using a power
Darlington with adequate heat sink in the output stage boosts
the output current I out1 above 1.0 A.
of Q1 by means of the sensing resistor, R SC :
The voltage protection circuit performs a foldback
characteristic above a nominal operating voltage, V CC2
18 V.
Delay and Watchdog Circuit
V out1 and releases the delay circuit RESET as soon as the
regulator output reaches the microprocessor operating a
range [e.g., V low
an open–collector and may be connected in a “wired–OR”
configuration.
monostable with a negative edge sensitive control input WDI.
The watchdog feature may be disabled by means of the
watchdog select input WDS driven to a “1”. Figure 17 displays
the Typical RESET Timing Diagram.
voltage V C5(L) , V C5(H) and an external capacitor C5 define
the RESET delay and the watchdog timing. The relationship
of the timing signals are indicated by the Equations (9) to (11).
Watchdog timeout:
Watchdog RESET:
[I C5 , V C5(H) , V C5(L) : see Electrical Characteristics Table]
Together with an external PNP power transistor (Q1), a
The current limitation circuit measures the emitter current
The undervoltage monitor supervises the power supply
The watchdog circuit consists of a retriggerable
The commuted current source I C5 on Pin 17, threshold
RESET delay:
[I E : emitter current of Q1]
[V RSC : threshold voltage
[V RSC :
(see Electrical Characteristics Table)]
w
MOTOROLA ANALOG IC DEVICE DATA
0.93 V out1(nom) ]. The RESET output has
R SC =
t d =
t wd =
t r =
C5 V C5(H)
C5 (V C5(H) – V C5(L) )
C5 (V C5(H) – V C5(L) )
V RSC
|I C5 |
I E
50
5 I C5
|I C5 |
(10)
(11)
(8)
(9)