MAX5943AEEE+ Maxim Integrated Products, MAX5943AEEE+ Datasheet - Page 18

• Manufacturer Part Number: MAX5943AEEE+
• Description: IC FIREWIRE CURR LIMITER 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX5943AEEE+

• 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

FireWire Current Limiter and Low-Drop
ORing Switch Controller
The MAX5943 serves to regulate and protect FireWire
power over a system interface. The MAX5943 program-
mable features make it suitable for both power provider
and power receiver applications. Figure 14 shows a
high-end two-port FireWire power management system
using two MAX5943As and a dual-channel MAX5944
FireWire current-limiting IC.
If IN or OUT experiences a fast voltage transient, the
drain-to-gate parasitic capacitance of Q1 and/or Q2
may be sufficient to briefly enhance one of the transis-
tors, allowing current glitch. If the circuit is subjected to
large transients, connect capacitors from the gate to
source across the appropriate MOSFET, preventing the
parasitic capacitance from turning on the device.
18
FireWire
PORT
SUPPLY
CURRENT-LIMIT/CIRCUIT-BREAKER
AND INRUSH CONTROL
R1
R2
______________________________________________________________________________________
VERY-LOW-DROP
ORing DIODE
R3
FAULT
ON
TIM
Typical Operating Circuit
ILIM
MAX5943 EQUIVALENT CIRCUIT
IN
FireWire Power Management
+
R
SENSE
V
LATCH
IS
-
SENSE GATE1
MAX5943A
Transient Protection
GND
OR_ADJ
Q1
GATE2
LOAD DISCONNECT
SWITCH
ONQ1
Q2
OUT
TO
FireWire
PORT
Caution: The additional gate-to-source capacitance
causes the turn-off time of the MOSFETs to increase
due to the additional charge of the capacitor. Use the
minimum capacitor value to prevent currents from flow-
ing in hot-plug situations.
TRANSISTOR COUNT: 2324
PROCESS: BiCMOS
MAX5943C Circuit breaker
MAX5943D Circuit breaker
MAX5943A
MAX5943B Circuit breaker
MAX5943E Circuit breaker
FireWire
PORT
SUPPLY
V
7.15kΩ
PART
IN
+
-
1kΩ
= 12V
10kΩ
Typical Application Circuit
Current limit
CURRENT
BREAKER
LIMITER/
4kΩ
CIRCUIT
FAULT
ON
TIM
ILIM
IN
30mΩ
LATCH
DEFAULT
TIMEOUT
SENSE GATE1
Chip Information
MAX5943A
(ms)
0.5
GND
2
1
2
4
SI7958DP
Selector Guide
OR_ADJ
Q1
PROGRAMMABLE
TIMEOUT RANGE
1.04ms to 11.05ms
SI7958DP
130µs to 1.38ms
260µs to 2.76ms
32.5µs to 345µs
GATE2
65µs to 690µs
ONQ1
Q2
OUT
TO
FireWire
PORT