cs5257a-1 ON Semiconductor, cs5257a-1 Datasheet - Page 6

• Manufacturer Part Number: cs5257a-1
• Description: 7.0 A Ldo 5?pin Adjustable Linear Regulator
• Manufacturer: ON Semiconductor

voltages from 1.25 V to 5.0 V at currents up to 7.0 A. The
regulator is protected against short circuits, and includes a
thermal shutdown circuit with hysteresis. The output, which
is current limited, consists of a PNP − NPN transistor pair
and requires an output capacitor for stability. A detailed
procedure for selecting this capacitor is included in the
Stability Considerations section.
V
maximize efficiency. The collector of the power device is
brought out to the V
dissipation under high current loads. V
power for the control circuitry and the drive for the output
NPN transistor. V
than the output voltage. Special care has been taken to ensure
that there are no supply sequencing problems. The output
POWER
The CS5257A−1 linear regulator provides adjustable
The CS5257A−1 utilizes a two supply approach to
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
Figure 13. V
Function
V
CONTROL
1.0
THEORY OF OPERATION
CONTROL
= 2.75 V
POWER
2.0
POWER
Output Current (A)
3.0
pin to minimize internal power
should be at least 1.0 V greater
Dropout Voltage vs I
4.0
77
76
75
74
73
72
Figure 15. Adjust Pin Current vs Output Current
0
CONTROL
V
V
POWER
CONTROL
5.0
1.0
APPLICATIONS NOTES
= 2.05 V
6.0
2.0
provides
OUT
= 2.75 V
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Output Current (A)
3.0
7.0
6
4.0
Figure 14. Minimum Load Current vs V
916.4
916.3
916.2
916.1
916.0
915.9
915.8
915.7
915.6
915.5
915.4
voltage will not turn on until both supplies are operating. If
the control voltage comes up first, the output current will be
typically limited to about 3.0 mA until the power input
voltage comes up. If the power input voltage comes up first
the output will not turn on at all until the control voltage
comes up. The output can never come up unregulated.
device with the control and power inputs tied together. In
this mode, the dropout will be determined by the minimum
control voltage.
Output Voltage Sensing
dedicated V
sensing of the output voltage. This feature can virtually
eliminate errors in the output voltage due to load regulation.
Regulation will be optimized at the point where the sense pin
is tied to the output.
The CS5257A−1 can also be used as a single supply
The CS5257A−1 five terminal linear regulator includes a
0.5
5.0
V
DV
CONTROL
6.0
OUT
SENSE
= +1.0%
1.5
7.0
= 5.0 V
function. This allows for true Kelvin
V
POWER
8.0
2.5
− V
OUT
(V)
POWER
3.5
− V
OUT
4.5