Linear Technology LTC2928 Quick Start Manual

DESCRIPTION
Demonstration circuit 1029B is for evaluating the per-
formance of the LTC 2928
®
Sequencer and Supervisor.
The LTC2928 sequences and monitors up to four power
channels in power-up and power-down, and it monitors
those outputs in the steady state. Sequencing is accom-
plished by controlling the power supply enable inputs or
N-channel MOSFET gates with the LTC2928 outputs. Su-
pervisory functions include undervoltage and overvoltage
monitoring, and capturing the output state information in
the event of a system fault.
Inherent fault detection circuitry can detect:
Stalled supplies (during sequencing)
n
Supplies with the output voltage not satisfying the
n
undervoltage or overvoltage conditions
PERFORMANCE SUMMARY
SYMBOL PARAMETER
V V Input Supply Range
CC CC
VHV HV Input Supply Range
CC CC
V ON Threshold Voltage
ON
V Voltage Monitor Reset Threshold Voltage
MON(TH)
V Enable Pin Voltage Output in ON State
EN
I Enable Pin Pull-Up Current
EN(UP)
t Sequence Timer Period, STMR
STMR
t Power Good Timer Period
PTMR
t Reset Timer
RTMR
V1 V1 Internal and External Input
V2 V2 Internal and External Input
V3 V3 Internal and External Input
V4 V4 Internal and External Input
TPV1 V1 Time Position
TPV2 V2 Time Position
TPV3 V3 Time Position
TPV4 V4 Time Position
Multichannel Power Supply
Specifications are at T
CONDITIONS
V Rising
ON
VSEL = V
Enable Pin ON, V
C = 0.022µF
STMR
C = 2.2µF
PTMR
C = 0.047μF
RTMR
DEMO MANUAL DC1029B
Multichannel Power Supply
Sequencer and Supervisor
System controller command errors
n
Externally commanded faults
n
Sequencing faults
n
The board is populated with nineteen jumpers for selection
of the LTC2928 operation options and with twelve LEDs
for displaying:
The undervoltage status in the steady state
n
CMP1 (D5) – CMP4 (D8)
The LTC2928 controlling outputs states
n
EN1 (D1) – EN4 (D4)
The state signals of the ON pin (#16), the RST
n
pin (#21), the OV pin (#20), and the FLT pin (#19).
Design files for this circuit board are available at
http://www.linear.com/demo/DC1029B
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
= 25°C
A
MIN
2.9
7.2
0.985
0.492
CC
V + 4.5
CC
≤ V + 4V –7.5
EN CC
161
7.33
156.7
LTC2928
TYP MAX
6.0
12.0 16.5
1.0 1.15
0.500 0.508
V + 5.5 V + 6
CC CC
–10 –12.5
190 220
8.80 10.27
188.0 219.3
2.5
1.5
1.8
3.3
1
3
5
7
UNITS
V
V
V
V
V
µA
ms
s
ms
V
V
V
V
dc1029bf
1