• Four 8-Bit DACS
– Differential Non-linearity - ±0.5LSB max
– Integral Non-Linearity - ±1LSB max
• Each DAC has Independent Reference Inputs
– Output Buffer Amplifiers Swing Rail-to-Rail
– Ground to VDD Reference Input Range
• Each DAC’s Digital Input Data Maintained in
Nonvolatile EEPROM
• Power-On Reset Reloads Registers with
Nonvolatile Data
• Simple Serial Interface for Reading and Writing
DAC values, SPI™ and QSPI™ compatible.
• Fully operational from 2.7V to 5.5V
• Low Power: <1mW @ 2.7V
FUNCTIONAL BLOCK DIAGRAM
Memory Control
8-Bit E2PROM
OVERVIEW
The S9408 DACPOT™ is a serial input, voltage output,
quad 8-bit digital to analog converter. The S9408 oper-
ates from a single +2.7V to +5.5V supply. Internal precision buffers swing rail-to-rail and the reference input
range includes both ground and the positive supply.
The S9408 integrates four 8-bit DACs and their associated circuits which include an enhanced unity-gain opera-
tional amplifier output, an 8-bit data latch, an 8-bit nonvolatile register, and an industry-standard serial interface
for reading and writing data to the DACs’ data latches and
registers. The DACs are independently programmable
and each has its own electrically isolated Vreference
inputs.
power mode
7DIData Input: serial data input pin
8DOData Output: serial data output pin
900/REG#Power On Recall Option Input
10GNDPower Supply Ground
11, 12V
REFL
13, 14V
15, 16V
OUT
Vreference Low:
REFH
> V
REFL
• GND
DAC Output: buffered D to A
17, 18converter output
The analog outputs of the S9408 can be programmed to
any one of 256 individual voltage steps. Each step value
is 1/256th of the voltage differential between V
V
of the respective DAC. Once programmed these
REFL
REFH
and
settings can be retained in nonvolatile memory during all
power conditions and will be automatically recalled upon
a power-up sequence. Each DAC can be independently
read without affecting the output voltage during the read
cycle. In addition, each output can be adjusted an unlimited number of times without altering the value stored in
the nonvolatile memory.
DEVICE OPERATION
Analog Section
The S9804 is an 8-bit, voltage output digital-to-analog
converter (DAC). The DAC consists of a resistor network
that converts 8-bit digital inputs into equivalent analog
output voltages in proportion to the applied reference
voltage.
Reference inputs
The voltage differential between the V
REFL
and V
REFH
inputs sets the full-scale output voltage for its respective
DAC. V
(positive voltage). V
than V
must be equal to or greater than ground
REFL
must be greater (more positive)
REFH
and less than or equal to VDD.
REFL
Output Buffer Amplifiers
The voltage outputs are precision unity-gain followers that
slew up to 1V/µs. The outputs can swing from V
V
. With a 0V to 5V output transition the amplifier
REFH
REFL
to
outputs typically settle to 1LSB in 40µs.
DIGITAL INTERFACE
The S9408 employs a common 4-wire serial interface. It
is comprised of a Clock (CLK), Chip Select (CS#), Data In
(DI) and Data Out (DO). Data is clocked into the device on
the clock’s rising edge and out of the device on the clock’s
falling edge. Data is shifted in and out MSB first. DO only
becomes active after the device has been selected and
after a valid read command and address has been received.
All data transfers are initiated after CS# goes low and a
logic ‘1’ is clocked into the device. This first data transfer
is the start bit and must precede all operations. Following
the start bit are two command bits used to specify which
of four commands to execute. The next two bits are the
address bits used to select one of the four DACs. The
action of the next eight clock cycles will be dependent
upon the command issued.
Internally there are four DACs and associated with each
are two registers. There is one data register that is used
by the DAC to hold the digital value it converts. There is
also one nonvolatile register that holds the default value
that can be recalled into the data register during powerup or by executing the Recall command.
READ
Read operations are initiated by taking CS# low and
clocking in a start bit followed by the read command and
the address of the data register to be read. The next eight
clocks will output on the DO pin the contents of the
selected data register. This read will not affect the contents
of the register or the output of the DAC. Refer to Figure 1
for an illustration of the sequence of bus conditions for a
read operation.
WRITE
Write operations are initiated by taking CS# low and
clocking in a start bit followed by the write command and
the address of the data register to be written. This action
is followed by the host clocking eight bits of data into the
register, MSB first. The output of the selected DAC will
change as the last bit is clocked into the device. At this
point the clock counter will reset the command register,
requiring a full sequence to be initiated in order to write to
the DAC again.
NOTE: This write operation does not affect the
contents of the nonvolatile register. Therefore, the
nonvolatile register can contain the power-on default
settings (e.g. volume), and the write DAC command
can be used to make situational adjustments.
Refer to Figure 2 for an illustration of the sequence of bus
conditions for a write operation.
CS#
CLK
DI
S
T
A
R
T
DO
RDY/BSY#
SUMMIT MICROELECTRONICS, Inc.
CACA
1100
Hi Z
(Pulled up to VDD)
FIGURE 1. READ SEQUENCE
DD
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DDDDDD
10345672
2015 T fig01 2.0
Hi Z
3
Page 4
CS#
CLK
S9408
DI
DO
RDY/BSY#
VOUT
CS#
CLK
DI
S
T
A
R
T
CC
10
CDACDA
Hi Z
Rising Edge Sets
NV Write Enable Latch
A
Address and Data
are Don’t Care
D
01
(Pulled up to VDD)
FIGURE 2. WRITE SEQUENCE
CC
10
DDDDDD
DADA
DDDDDD
103456711200
Rising Edge Starts
NV Write
1034567120
2015 T fig02 2.0
NV Write Enable
Latch is Reset
RDY/BSY#
FIGURE 3. NONVOLATILE WRITE SEQUENCE
NONVOLATILE WRITE
A nonvolatile write is a two step operation: it is initiated by
taking CS# low and clocking in a start bit followed by the
NV Enable command. At this point the host can take CS#
back high or continue clocking in data. This data is don’t
care and will be ignored by the S9408. If any command
other than write follows NV enable the NV latch will be
cleared.
Next, the host takes CS# low again and issues a write
command and address and then clocks in the eight data
4
2015 2.2 8/2/00
2015 T fig03 2.0
bits to be programmed. The host will then bring CS# HIGH
and the data will be latched into the data register and a
nonvolatile write operation will commence.
The status of the nonvolatile write can be monitored on the
RDY/BSY# pin. A logic low indicates the write is still in
progress and the S9408 will not be accessible to the host;
a logic high indicates the write has completed and the
S9408 is ready for the next command. Refer to Figure 3
for an illustration of the sequence of bus conditions for a
nonvolatile write operation.
SUMMIT MICROELECTRONICS, Inc.
Page 5
S9408
RECALL COMMAND
The recall command will retrieve data from the selected
nonvolatile register and write it into the data register of the
associated DAC. This operation is initiated by taking CS#
low and clocking in a start bit followed by the recall
command and the address of the nonvolatile register to be
recalled. The eight bits of data are don’t care, so CS# can
be taken high any time after the address bits are clocked
in. Refer to Figure 4 for an illustration of the sequence of
bus conditions for a Recall operation.
CS#
CLK
S
T
A
R
T
CACA
1100
V
DI
OUT
Power-on recall
Whenever the S9408 is powered on the DAC output
values will be returned to the selected default setting. The
default setting can be the nonvolatile register contents or
all zeroes. The state of the 00/REG# pin will determine
which operation will be performed. If it is tied to ground (or
left floating) the nonvolatile register contents will be recalled. Conversely, if it is tied to VDD the S9408 will recall
zeroes.
FIGURE 4. RECALL COMMAND SEQUENCE
2015 T fig04 2.0
SUMMIT MICROELECTRONICS, Inc.
2015 2.2 8/2/00
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Page 6
S9408
ABSOLUTE MAXIMUM RATINGS
VDD to GND .................................................................... -0.5V to +7V
Digital Inputs to GND ............................................ -0.5V to VDD+0.5V
Analog Inputs to GND........................................... -0.5V to VDD+0.5V
Digital Outputs to GND ......................................... -0.5V to VDD+0.5V
Analog Outputs to GND ........................................ -0.5V to VDD+0.5V
Temperature Under Bias ........................................... -55°C to +125°C
Storage Temperature ................................................-65°C to +150°C
Lead Soldering (10 Sec Max) .................................................... 300°C
Stresses listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions outside those
listed in the operational sections of this specification is not implied.
Exposure to any absolute maximum rating for extended periods may
affect device performance and reliability.
+2.7V+5.5V
2015 PGM T2 1.2
V
PAZ
I
HTL
T
RD
N
DNE
ytilibitpecsuSDSE0002V
pu-hctaL001Am
noitneteRataD001sraeY
ecnarudnE000,000,1selcyCegarotS
DC ELECTRICAL CHARACTERISTICS (Over recommended operating conditions unless otherwise specified)
Note 1: IDD is the supply current drawn while the EEPROM is being updated.
6
2015 2.2 8/2/00
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Page 7
S9408
AC ELECTRICAL CHARACTERISTICS
VDD = +4.5V to +5.5V, V
SymbolParameterConditionsMin.Typ.Max.Units
REFH
= VDD, V
= 0V, TA = -40°C to +85°C, unless otherwise specified
REFL
f
C
t
WH
t
WL
t
CS
t
CSS
t
CSH
t
SU
t
H
t
V
t
HO
t
DIS
t
BUSY
Notes: 1. All timing measurements are defined at the point of signal crossing VDD/2.
Clock FrequencyDC1MHz
Minimum CLK High Time500ns
Minimum CLK Low Time300ns
Minimum CS High Time150ns
CS Setup Time100ns
CS Hold Time0ns
Data In Setup TimeCL = 100pF50ns
Data In Hold TimeSee Note 150ns
Output Valid Time150ns
Data Out Hold Time0ns
Output Disable Time400ns
Write Cycle Time3.35ms
2015 PGM T5 1.1
t
CS
CS#
CLK
DI
DO
RDY/BSY#
t
t
CSS
t
t
SU
Hi Z
H
t
WL
t
V
WH
t
CSH
t
t
HO
DIS
Hi Z
2015 T fig05 2.0
FIGURE 5. AC TIMING DIAGRAM
SUMMIT MICROELECTRONICS, Inc.
2015 2.2 8/2/00
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Page 8
DAC DC ELECTRICAL CHARACTERISTICS
VDD = 2.7V to 5.5V, V
REFH
= VDD, V
= 0V, TA = -40°C to +85°C, unless otherwise specified
REFL
ytreporPlobmySretemaraPsnoitidnoCniMpyTxaMtinU
S9408
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ycaruccA
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V
HFER
V
LFER
R
secnerefeR
NI
∆R
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V
I
L
R
V
HFER
RCT
NI
NI
SFE
SZegatlovtesffotuptuO00=D
TUO
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egatlovtupnIV
egatlovtupnIDNGV
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LFER
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tnerrucdaoltuptuopmA002–0001Aµ
ecnatsisertuptuopmA
DAOL
DAOL
V
DD
I
DAOL
Aµ001=5.01±BSL
)1eton(Aµ001=1.05.0±BSL
LFER
003006Cº/mpp
XEH
XEH
I,V5=
DAOL
Aµ05=
05.25 Vm
)1eton(
Aµ001=V5
V3
01
02
V
DD
hFER
1±BSL
05Cº/Vµ
V
V
Ω
Ω
Ω
golanA
tuptuO
RRSPnoitcejerylppusrewoPI
t
S
BSL1otemitgnilttesCAD
DAOL
Aµ01=1V/BSL
Fp01V5
V3Fp01
63
72
0453
sµ
sµ
e
N
DHTnoitrotsidcinomrahlatoT
WBBd3–htdiwdnaB
Note 1: Guaranteed but not tested
esiontuptuopmAV,zHk1=f
V5=09Vn √ zH
DD
V
HFER
V
HFER
V
NI
V,V5.2=
V,zHk1=f
NI
V,V5.2=
Vm001=
SMR
,V5=
DD
V1=
SMR
,V5=
DD
80.0%
003zHk
8
2015 2.2 8/2/00
SUMMIT MICROELECTRONICS, Inc.
Page 9
S9408
20 Pin SOIC (.300) Package
0.291 - 0.299
(7.391 - 7.595)
0.010 - 0.029
(0.254 - 0.737)
0.009 - 0.013
(0.229 - 0.330)
x45°
0.016 - 0.050
(0.406 - 1.270)
0° to 8°
typ
0.093 - 0.104
(2.362 - 2.642)
0.050
(1.270)
0.496 - 0.512
(12.598 - 13.005)
0.014 - 0.019
(0.356 - 0.482)
0.394 - 0.419
(10.007 - 10.643)
0.037 - 0.045
(0.940 - 1.143
0.004 - 0.012
(0.102 - 0.305)
41.5
41.0
40.5
40.0
RESISTANCE (kΩ)
39.5
39.0
–4090
TEMPERATURE (ºC)
VL = GND
VH = 5.5V
VH = 4.5V
VH = 2.7V
25
FIGURE 6. VL to VH END-TO-END RESISTANCE
OVER TEMPERATURE
20pn SOIC ILL.1
2015 T fig06 2.0
SUMMIT MICROELECTRONICS, Inc.
2015 2.2 8/2/00
9
Page 10
ORDERING INFORMATION
S9408
Base Part Number
S9408
Special order
*
P
Package
P = 20 Pin PDIP
S = 20 Pin SOIC
2015 T ree 2.0
*
NOTICE
SUMMIT Microelectronics, Inc. reserves the right to make changes to the products contained in this publication in order
to improve design, performance or reliability. SUMMIT Microelectronics, Inc. assumes no responsibility for the use of
any circuits described herein, conveys no license under any patent or other right, and makes no representation that
the circuits are free of patent infringement. Charts and schedules contained herein reflect representative operating
parameters, and may vary depending upon a user’s specific application. While the information in this publication has
been carefully checked, SUMMIT Microelectronics, Inc. shall not be liable for any damages arising as a result of any
error or omission.
SUMMIT Microelectronics, Inc. does not recommend the use of any of its products in life support or aviation applications
where the failure or malfunction of the product can reasonably be expected to cause any failure of either system or to
significantly affect their safety or effectiveness. Products are not authorized for use in such applications unless
SUMMIT Microelectronics, Inc. receives written assurances, to its satisfaction, that: (a) the risk of injury or damage has
been minimized; (b) the user assumes all such risks; and (c) potential liability of SUMMIT Microelectronics, Inc. is
adequately protected under the circumstances.