ISL88694IH5Z-TK Intersil, ISL88694IH5Z-TK Datasheet - Page 6

• Manufacturer Part Number: ISL88694IH5Z-TK
• Description: IC ACCELERATOR SMBUS SOT23-5
• Manufacturer: Intersil
• Type: SMBus Acceleratorr

Specifications of ISL88694IH5Z-TK

• Tx/rx Type: I²C Logic
• Voltage - Supply: 2.7 V ~ 5.5 V
• Current - Supply: 80µA
• Mounting Type: Surface Mount
• Package / Case: SOT-23-5, SC-74A, SOT-25
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Delay Time: -
• Capacitance - Input: -
• Other names: ISL88694IH5Z; ISL88694IH5ZTR

ISL88694 Operation
To improve the operation of the SMBus where larger bus
capacitance exists, the ISL88694 provides active pull-up
using switched current sources. When the bus is idle and
both lines are HIGH, a standby pull-up current of 100µA is
used to maintain the signal level while minimizing power
consumption. When either of the two signals is pulled LOW,
an active pull-up current of 275µA maintains a good V
noise margin.
When the bus line is released, it is pulled high by the
ISL88694 active current until the voltage exceeds the
V
combination filters out noise on the signal line. Once the
ISL88694 detects a valid rising edge, a 2.2mA boost current
pulls the bus line high very quickly (see Figure 8). This boost
current turns off when the input level reaches the V
threshold and the pull-up current returns to the active level. If
both inputs are HIGH, the pull-up current drops to the
standby level of 100µA.
TRIPL
FIGURE 8. ISL88694 SMBus SYSTEM BOOST PULL-UP
level for a period of time. This voltage-time
V
R=15.8K
C= 200pF
TRIPL
COMPARED TO RESISTOR PULL-UP (V
5.5V).
V
TRIPH
With ISL88694 SMA
6
With RC
Pullup
TRIPH
DD
OL
=
ISL88694
FIGURE 10. NOISE SUPPRESSION. BOOST CURRENT
FIGURE 9. ISL88694 SMBus SYSTEM BOOST PULL-UP
SMBus1
SMBus2
V
V
V
Gnd
DD
TRIPH
TRIPL
V
R=15.8K
C= 200pF
TRIPL
V
TRIPH
COMPARED TO RESISTOR PULL-UP (V
2.7V).
APPLIED WHEN INPUT SIGNAL EXCEEDS 20Vns
(TYPICAL).
Without SMA
With ISL88694 SMA
>20Vns
(Typical)
With RC
Pullup
With SMA
t
January 21, 2005
DD
FN8239.1
=