LTC2924CGN#PBF Linear Technology, LTC2924CGN#PBF Datasheet - Page 10

• Manufacturer Part Number: LTC2924CGN#PBF
• Description: IC POWER SUPPLY SEQUENCER 16SSOP
• Manufacturer: Linear Technology

Specifications of LTC2924CGN#PBF

• Applications: Power Supply Sequencer
• Voltage - Supply: 3 V ~ 6 V
• Current - Supply: 1.5mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP
• Input Voltage: 6V
• Output Current: 10µA
• Output Voltage: 4.5V
• No. Of Outputs: 4
• Supply Voltage Range: 3V To 6V
• No. Of Pins: 16
• Operating Temperature Range: 0°C To +70°C
• Msl: MSL 1 - Unlimited
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -

LTC2924
APPLICATIO S I FOR ATIO
10
a Power On sequence (V
sequence (V
Referring to Figures 5 and 6, each set of resistors can
then be calculated by:
In the following example (Figure 5) I
corresponds to a R
R
R
B
A
=
=
Figure 5. Designing I
V
V
R
ON
ON
B
5V EARLY*
I
OFF
HYS
• .
–
– .
0 61
V
0 61
).
OFF
*5V EARLY MUST BE ON BEFORE
SEQUENCING SUPPLIES
CONTROLLER
V
U
HYS
I
SYSTEM
V
HYS
resistor of:
IN
+
–
POWER SUPPLY 1
ON
U
0.61V
POWER SUPPLY 3
HYS
POWER SUPPLY 2
POWER SUPPLY 4
) and Off during a Power Off
, Feedback Resistors
2924 F05
I
10k
HYS
W
10k
R
R
B
A
150nF
V
SHDN
HYS
PS
Figure 6. Typical Power Supply Sequencer
3.3V
I
I
RB
FB
SHDN
is 50µA. This
V
V
= I
ON
OFF
RB
= 2.2V
U
= 1V
150nF
+ I
5V
SHDN
HYS
1.6V
SHDN
2.5V
OUT1
OUT2
OUT3
OUT4
ON
DONE
FAULT
TMR
PGT
In Figure 5, V
provided above:
Hysteresis Voltage Check
After calculating the resistors R
sure the hystersis voltage at the ON and IN1-IN4 pins is
greater than 4mV. Use the following equation:
which is greater than 4mV.
For this example:
LTC2924
GND
V
R
R
R
V
V
CC
HYS
HYS
HYS
B
A
HYS/CFG
=
=
IN1
IN2
IN3
IN4
2 2
=
=
=
24
2 2
0.1µF
.
.
50
(
(
50
k
0 5
2 2
V
V
V
Ω
ON
.
ON
.
µ
9 2
µ
–
– .
V
A
.
• .
V
A
= 2.2V and V
R
1
49.9k
0 61
2924 TA03
0 61
–
k
V
A
–
=
24.9k
9.31k
Ω +
V
1
=
+
10
OFF
V
V
V
R
24
)
k
24
B
)
• .
=
11.81k
Ω
15.8k
k
9 2
•
Ω
k
9 2
R
Ω
.
A
k
OFF
k
Ω
Ω
49.9k
7.87k
= 1V. Using the equations
B
=
and R
0 33
.
33.2k
8.45k
V
V
V
V
V
V
V
V
ON
OFF
ON
OFF
ON
OFF
ON
OFF
V
A
≥ 3.01V
≤ 2.68V
≥ 4.49V
≤ 3.99V
≥ 1.43V
≤ 1.27V
≥ 2.25V
≤ 2V
, check to make
2924fa