Linear Technology 1029 Quick Start Manual

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1029
Multi Channel Power Supply Sequencer and Supervisor
DESCRIPTION
Demonstration circuit 1029 is for evaluating the per-
formance of the LTC2928 Multichannel Power Supply
Sequencer and Supervisor.
The LTC2928 sequences and monitors up to four
power channels in power up and power down, and it
monitors those channel outputs in the steady state,
when power goes to loads. Sequencing is accom-
plished by controlling the power supply enable inputs
or N-channel MOSFET gates with the LTC2928 control-
ling outputs. Supervisory functions include undervolt-
age and overvoltage monitoring, and capturing the
output state information in the event of a system fault.
Inherent fault detection circuitry can detect:
Stalled (during sequencing) supplies
I
Supplies with the output voltage not satisfying the
I
undervoltage or overvoltage conditions
System controller command errors
I
PERFORMANCE SUMMARY
Specifications are at T = 25° C
A
SYMBOL PARAMETER
V V Input Supply Range
CC CC
V HV Input Supply Range
HVCC CC
V ON Threshold Voltage
ON
V Voltage Monitor Reset Threshold Voltage VSEL=V
MON(TH)
V Sequencing Thresholds
SEQ(TH)
0.67 V
MON(TH)
0.33 V
MON(TH)
0.1 V
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
Externally commanded faults
I
Sequencing faults.
I
The board is populated with nineteen jumpers for se-
lection of the LTC2928 operation options and with
twelve LEDs for displaying:
The undervoltage status in the steady state CMP1
I
(D5)-CMP4 (D8)
The LTC2928 controlling outputs states EN1 (D1)-
I
EN4 (D4),
The state signals of the ON pin (#16), the RST# pin
I
(#21), the OV# pin (#20), and the FLT# pin (#19).
Design files for this circuit board are available. Call the
LTC factory.
, LTC and LT are registered trademarks of Linear
Technology Corporation. ThinSOT and PowerPath
are trademarks of Linear Technology Corporation.
CONDITIONS
V Rising
•
ON
CC
Enable Pin ON, V V
EN•( ( CC+4)
C
STMR=0.022UF
C
PTMR=2.2UF
C
RTMR=0.047UF
LTC2928
MIN TYP MAX
2.9 6.0
7.2 12.0 16.5
1.3 1.8 2.3
0.492 0.500 0.508
0.315 0.333 0.351
0.149 0.167 0.185
0.032 0.05 0.068
V +4.5 V +5.5 V +6
CC CC CC
7.5 10 12.5
161 190 220
8.80 10.27
7.33
188.0 219.3
156.7
2.5
1.5
1.8
3.3
1
3
5
7
UNITS
V
V
V
V
V
V
V
uA
ms
s
ms
V
1