MCP4821-E/P Microchip Technology, MCP4821-E/P Datasheet - Page 19

• Manufacturer Part Number: MCP4821-E/P
• Description: IC DAC 12BIT W/SPI 8DIP
• Manufacturer: Microchip Technology

Specifications of MCP4821-E/P

• Number Of Converters: 1
• Package / Case: 8-DIP (0.300", 7.62mm)
• Settling Time: 4.5µs
• Number Of Bits: 12
• Data Interface: Serial, SPI™
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Resolution: 12 bit
• Interface Type: Serial (3-Wire, SPI, Microwire)
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power Dissipation (max): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4.1.3
The internal Power-on Reset (POR) circuit monitors the
power supply voltage (V
operation. The circuit also ensures that the DAC
powers up with high output impedance (<SHDN> = 0,
typically 500 k. The devices will continue to have a
high-impedance output until a valid write command is
received, and the LDAC pin meets the input low
threshold.
If the power supply voltage is less than the POR
threshold (V
in the Reset state. It will remain in that state until
V
received.
Figure 4-3
pulse and the duration required to cause a reset to
occur, as well as the relationship between the duration
and trip voltage. A 0.1 µF decoupling capacitor,
mounted as close as possible to the V
provide additional transient immunity.
FIGURE 4-3:
 2010 Microchip Technology Inc.
DD
> V
POR
10
5V
shows a typical power supply transient
8
6
4
2
0
POWER-ON RESET CIRCUIT
POR
and a subsequent write command is
Transients below the curve
will NOT cause a reset
= 2.0V, typical), the DAC will be held
1
V
Transients above the curve
will cause a reset
DD
Typical Transient Response.
T
Time
A
2
- V
= +25°C
POR
DD
Transient Duration
V
3
) during the device
DD
(V)
- V
4
POR
DD
5
V
POR
pin, can
4.1.4
The user can shut down the device using a software
command (<SHDN> = 0) or SHDN pin. During
shutdown mode, most of the internal circuits, including
the output amplifier, are turned off for power savings.
The internal reference is not affected by the shutdown
command. The serial interface also remains active,
allowing a write command to bring the device out of
Shutdown mode. There will be no analog output at the
V
tive load (500 ktypical.
output stage during Shutdown mode.
The condition of the Power-on Reset circuit during
Shutdown is as follows:
a)
b)
The device will remain in Shutdown mode until the
<SHDN> bit = 1 is latched into the device or SHDN pin
is changed to logic high. When the device is changed
from Shutdown to Active mode, the output settling time
takes < 10 µs, but greater than the standard active
mode settling time (4.5 µs).
FIGURE 4-4:
Mode.
OUT
MCP4801/4811/4821
Resistive String DAC
Turned off if shutdown occurred from the SHDN
pin
Remains turned on if the shutdown occurred
through software
pin, which is internally switched to a known resis-
OP
Amp
SHUTDOWN MODE
Control Circuit
Power-Down
Output Stage for Shutdown
Figure 4-4
Resistive
Load
DS22244B-page 19
shows the analog
500 k
V
OUT