PCAL9555AHF,128 NXP Semiconductors, PCAL9555AHF,128 Datasheet - Page 24

• Manufacturer Part Number: PCAL9555AHF,128
• Description: Interface - I/O Expanders
• Manufacturer: NXP Semiconductors

Specifications of PCAL9555AHF,128

• Rohs: yes
• Maximum Operating Frequency: 100 kHz
• Operating Supply Voltage: 1.65 V to 5.5 V
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Package / Case: HWQFN-24
• Operating Current: 160 mA
• Output Current: 25 mA
• Power Dissipation: 200 mW
• Product Type: I/O Expanders

NXP Semiconductors
PCAL9555A
Product data sheet
8.4 Device current consumption with internal pull-up and pull-down
resistors
The PCAL9555A integrates programmable pull-up and pull-down resistors to eliminate
external components when pins are configured as inputs and pull-up or pull-down
resistors are required (for example, nothing is driving the inputs to the power supply rails.
Since these pull-up and pull-down resistors are internal to the device itself, they contribute
to the current consumption of the device and must be considered in the overall system
design.
The pull-up or pull-down function is selected in registers 48h and 49h, while the resistor is
connected by the enable registers 46h and 47h. The configuration of the resistors is
shown in
If the resistor is configured as a pull-up, that is, connected to V
the V
appear as additional I
In the same manner, if the resistor is configured as a pull-down and the pin is held HIGH,
current will flow from the power supply through the pin to the V
will not be measured as part of I
through V
The pull-up and pull-down resistors are simple resistors and the current is linear with
voltage. The resistance specification for these devices spans from 50 k with a nominal
100 k value. Any current flow through these resistors is additive by the number of pins
held HIGH or LOW and the current can be calculated by Ohm’s law. See
graph of supply current versus the number of pull-up resistors.
DD
pin through the resistor to ground when the pin is held LOW. This current will
Figure
SS
.
All information provided in this document is subject to legal disclaimers.
6.
Low-voltage 16-bit GPIO with Agile I/O, interrupt and weak pull-up
DD
Rev. 1 — 3 October 2012
upsetting any current consumption measurements.
DD
, one must be mindful of the 200 mA limiting value
DD
SS
PCAL9555A
, a current will flow from
pin. While this current
© NXP B.V. 2012. All rights reserved.
Figure 24
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for a