Datasheet
Tsi205 Primary Side Monitor
Features
Description
The Tsi205 is designed to monitor parameters on
the high voltage primary side of an on-card power
system in a distributed power architecture.
•
•
•
•
•
•
Input voltage measurement (24 V or 48 V)
10-bit analog-to-digital converter (ADC)
Input voltage measurement accuracy 0.5%
Fuse status monitoring, high and low side
Primary current sensing and measurement
Primary side undervoltage, overvoltage and
brownout detection
In a typical 24 V or 48 V application, the Tsi205
measures input voltage and current and transmits
the digitized values through a serial interface to the
secondary side controller (Tsi257). Input
overvoltage (OV) and undervoltage (UV) detection
are provided, with programmable thresholds set by
external resistors.
•
•
Input UV shutdown accuracy <1%
Isolated PI-Link interface to secondary side
controller transmits primary voltage, current,
fuse status and input status data
•
•
Compatible with standard inrush limiters
Self-powered from 24 V or 48 V nominal
The Tsi205 provides on-off control for an isolated
power converter that supplies the intermediate bus
voltage for the card. The Tsi205 monitors the status
of up to four input fuses, both high side and low
side. Fuse status information is transmitted to the
secondary side through the serial PI-Link interface.
Applications
•
Telecom and datacom cards
ATCA (Advanced Telecom Compute
Architecture) systems
•
•
•
Industrial controllers
Single board computers
Figure 1 — Typical application circuit
+
+
0 V
(Battery
return)
R5
EMI
filter
Intermediate
bus (IB) brick
CIN
Enable
IB rail
Power connections
shown as
-
-
R4
R3
R1 R2
R17
OP1
Tsi205
VDD
VDDO
ENABLE
TX_H
R16
Seat
SHUNT
SEAT
(short pins)
TX_L
Brick
shutdown
signal
from
Tsi257
BUSOFF
FETA
OP2
UV
C6
R13
C9
VBATT
FUSE_H
FUSE_L
VBG
SENSE_P
SENSE_OUT
SENSE_IN
R15
R12
T1
R19
PI-Link
interface
to Tsi257
NC
R14
R8
C7
SENSE_N
POR
R6
R7
VSS
Isolation
circuit
(see Fig. 7)
VSSO
AUX
BIAS
R9
R10
C2
-48 V A
D1
C1
Primary
Secondary
Fuse A
R11
Inrush
limit
R18
Fuse B
controller
D2
-48 V B
MD502J
Note: High-side fuse monitoring is not shown – refer to Figure 8.
80C6000_MA001_01 April 2006
© Tundra Semiconductor Corporation
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