MAX5943DEEE+T Maxim Integrated Products, MAX5943DEEE+T Datasheet - Page 17

• Manufacturer Part Number: MAX5943DEEE+T
• Description: IC FIREWIRE CURR LIMITER 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX5943DEEE+T

• Applications: FireWire® Apps
• Fet Type: N-Channel
• Number Of Outputs: 2
• Internal Switch(s): No
• Delay Time - Off: 100ns
• Voltage - Supply: 7.5 V ~ 37 V
• Current - Supply: 1.3mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Delay Time - On: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The programmable timeout of the MAX5943 allows the
use of MOSFETs with low power ratings. A MOSFET
typically withstands single-shot pulses with higher dis-
sipation than the specified package rating.
A single-port FireWire protective circuit employing the
MAX5943A has been UL recognized as a result of
extensive safety testing by Underwriters Laboratories. It
is the circuits themselves, not any individual component
Figure 13. Power Dissipated Across MOSFETs During a Short-
Circuit Fault for MAX5943B–MAX5943E
Figure 14. Two-Port FireWire Power Provider Using MAX5943A and MAX5944
SOURCE
BATTERY-
POWER
SOURCE
CABLE
POWER
V
IN
POWER OUT
CABLE
IN
ON
PHY
R
SLEEP
NOT
SENSE
ON
ON
MAX5943B–MAX5943E
TIM
TIM
SENSE GATE1
______________________________________________________________________________________
ILIM
ILIM
IN
IN
FireWire Current Limiter and Low-Drop
R
DS(ON)1
15mΩ
15mΩ
LATCH
LATCH
SENSE GATE1
SENSE GATE1
MAX5943A
MAX5943A
GND
GND
R
GATE2
DS(ON)1
SI7958DP
SI7958DP
FB
BST
LX
ONQ1
ONQ1
OUT
GND
MAX5033
SI7958DP
SI7958DP
GATE2 OUT
GATE2 OUT
ISC
OR_ADJ
OR_ADJ
SGND
FAULT
FAULT
V
ON
CURRENT-LIMIT
VD
IN
SENSE
ORing Switch Controller
IN4148
thereof, that are UL recognized. The circuit is further
described in Application Note 3984— UL Recognized,
IEEE 1394 Single- and Dual-Port FireWire Protective
Circuits available at www.maxim-ic.com/appnotes.cfm/
appnote_number/3984.
The circuit provides:
•
•
•
•
•
•
•
2.5A (adjustable) current limiting to the load at initial
connection or in overload fault condition
2ms (adjustable) current-limit timeout before load
disconnect for excessive load current
Automatic-restart attempts after a fault shutdown
condition
<0.8% current-limited duty cycle in continuous fault
condition
6.5V undervoltage shutdown protection
Low-drop ORing in multiple power-source applica-
tions, and
Fault reporting
ONA
ONQ1
GND
ONB
INB
INA
IN4148
30mΩ
30mΩ
SENSEB GATE1B
SENSEA GATE1A
MAX5944
SI7958DP
IRF7478
SI7958DP
GATE2B OUTB
IRF7478
GATE2A OUTA
FAULTA
FAULTB
IN4148
IN4148
PORT 1
SENSE
PORT 0
SENSE
CPA SENSE
PORT 0
PORT 1
17