AS1542-BTSU ams, AS1542-BTSU Datasheet - Page 22

• Manufacturer Part Number: AS1542-BTSU
• Description: Analog to Digital Converters - ADC
• Manufacturer: ams

Specifications of AS1542-BTSU

• Rohs: yes
• Number Of Channels: 16/8
• Architecture: SAR
• Conversion Rate: 1 MSPs
• Resolution: 12 bit
• Input Type: Single-Ended/Differential
• Snr: 71 dB
• Interface Type: QSPI, SPI
• Operating Supply Voltage: 2.7 V to 5.25 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-28
• Maximum Power Dissipation: 18.4 mW
• Minimum Operating Temperature: - 40 C
• Number Of Converters: 1

AS1542
Data Sheet - D e t a i l e d D e s c r i p t i o n
However, if bit WEAK/TRIN is set to 1, then although DOUT is driven with address bit ADDR3 since the last conver-
sion, it is nevertheless so weakly driven that another device may still take control of the bus. It will not lead to a bus
contention (e.g., a 10 kΩ pull-up or pull-down resistor would be sufficient to overdrive the logic level of ADDR3
between conversions) and all 16 channels may be identified. However, if this does happen and another device takes
control of the bus, it is not guaranteed that DOUT will be fully driven to ADDR3 again in time for the read operation
when control of the bus is taken back.
This is useful if using an automatic sequence mode to identify channel-result pairs. Obviously, if only the first eight
channels are in use, then address bit ADDR3 does not need to be decoded, and whether it is successfully clocked in
as a 1 or 0 will not matter as long as it is still counted by the DSP as the MSB of the 16-bit serial transfer.
Power Modes
The AS1542 can be operated in 2 different modes:
These modes are designed to provide flexible power management options, and can be selected to optimize the power
dissipation and throughput-rate ratio for differing application requirements. The mode of operation of the AS1542 is
controlled by bits
Note: When power supplies are first applied to the AS1542, internal power-on reset circuitry sets the device for Auto
Normal Mode (PM1 = 1, PM0 = 1)
This mode is intended for the fastest throughput rate performance as the user does not have to worry about any
power-up times with the AS1542 remaining fully powered at all times.
normal mode.Conversion is initiated on the falling edge of CSN and the track and hold will enter hold mode.
The data presented to pin DIN during the first 13 clock cycles of the data transfer is loaded to the control register (if bit
WRITE (page 14)
sented on pin DIN during the first 16 SCLK cycles is loaded into the shadow register. The device will remain fully
powered up in normal mode at the end of the conversion as long as bits
transfer during that conversion.
To ensure continued operation in normal mode, bits PM1 and PM0 are loaded with 1 on every data transfer. Sixteen
serial clock cycles are required to complete the conversion and access the conversion result. The track and hold will
go back into track on the 14th SCLK falling edge.
Once a data transfer is complete (DOUT has returned to tri-state, bit
can be initiated after the quiet time (t
Figure 33. Normal Mode Operation
Notes:
1. Control register data is loaded on the 1st 13 SCLK cycles.
2. Shadow register data is loaded on the 1st 16 SCLK cycles.
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- Normal Mode
- Auto Shutdown
Shutdown (PM1 = 0, PM0 = x). The AS1542 remains in shutdown the first CSN falling edge is received.
DOUT
SCLK
CSN
DIN
PM1, PM0 (page 14)
is set to 1). If bit
(see page 22)
(see page 23)
SEQ (page 14)
QUIET
of the control register.
) has elapsed by bringing CSN low again.
Channel ID Bits + Conversion Results
Data into Control/Shadow Register
= 0, and bit
Revision 1.00
SHADOW (page 14)
WEAK/TRIN (page 14)
Figure 33
PM1, PM0 (page 14)
shows the operation of the AS1542 in
= 1 on the previous write, data pre-
= 0), another conversion
are set to 1 in the write
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