SA5777AD [NXP]
Dual air-core gauge driver; 双空芯仪驱动程序
| 型号： | SA5777AD |
| 厂家： | 
NXP |
| 描述： | Dual air-core gauge driver |
| 文件： | 总12页 (文件大小：120K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
INTEGRATED CIRCUITS
SA5777A
Dual air–core gauge driver
Product specification
1999 Sep 20
Supersedes data of 1997 Feb 24
Philips
Semiconductors
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
DESCRIPTION
PIN CONFIGURATION
The SA5777A is a monolithic driver for controlling air-core (or
differential) meters typically used in automotive instrument cluster
applications. The circuit interfaces with a microprocessor through a
serial bus and directly drives the air-core meter. The SA5777A has
10-bit resolution (0.35 degree) and is guaranteed to be monotonic.
Data can be shifted through the part, allowing several SA5777As to
be cascaded with only one chip-select line. On-chip current shut
down logic protects the circuit from external faults.
N Package
1
16
15
14
13
12
11
10
9
C2+
C2-
C1–
C1+
2
3
4
5
6
7
8
A
GND
COM
V
A
BB
GND
D
DATA
GND
OUT
FEATURES
• 10-Bit resolution (0.35 degrees)
ST
CS
DATA
IN
V
CC
OE
• Exceptional accuracy (0.5 degrees, typical)
• High-torque capability
S
CLK
• Active differential drivers eliminate back-EMF issues
• No RFI/EMI generation issues
D Package
• Simple serial interface
1
28
C1–
C1+
C2+
2
3
27 C2-
26 NC
• Simple cascading capability for multiple meters
• Internal fault protection
NC
NC
4
25
24
23
22
21
20
19
18
17
16
15
NC
• Only one external component required (bypass capacitor)
5
NC
COM
A
6
A
GND
GND
NC
7
V
APPLICATION
BB
NC
8
DATA
• Instrumentation utilizing air-core meters
OUT
9
DATA
D
IN
GND
10
11
12
13
14
NC
ST
NC
NC
NC
NC
CS
S
V
CC
OE
CLK
SL00460
Figure 1. Pin configuration
ORDERING INFORMATION
DESCRIPTION
TEMPERATURE RANGE
ORDER CODE
SA5777AN
DWG #
SOT38-4
SOT136-1
-40 to +85°C
-40 to +85°C
16-Pin Plastic Dual In-Line Package (DIP)
28-Pin Plastic Small Outline Package (SO)
SA5777AD
2
1999 Sep 20
853-1930 022368
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
BLOCK DIAGRAM
V
BB
OE
V
BB
C2+
C2–
7 + – BIT
DAC
MUX
COM
V
/2
BB
8
7 + – BIT
DAC
MUX
C1+
C1–
8
FAULT
DETECTION
ST
9-BIT LATCH
9-BIT LATCH
CS
V
CC
D
10-BIT
10-BIT
IN
D
SHIFT REGISTER
SHIFT REGISTER
OUT
S
CLK
SL00461
Figure 2. Block diagram
Table 1. SA5777A Pin Descriptions for the N Package (Dual In-Line)
Pin #
1.
Name
C1–
Function
Negative output connection to the TAN coil of meter #1.
Positive output connection to the TAN coil of meter #1.
2.
C1+
3.
A
GND
Ground for V supply. Pins 3, 12 and 13 should be connected on the circuit board.
BB
4.
V
BB
Analog supply. Nominally 13.5 V.
DATA
Serial data output. Output of the internal shift register. When a new data word is shifted in, the old word is shifted out the
DATA pin. DATA output is always active.
OUT
5.
6.
OUT
OUT
DATA
Serial data input. A new data word is serially shifted into the part on the rising edge of S
first, gauge 1 first.
. The data is shifted in MSB
CLK
IN
7.
8.
V
5 V logic supply. The internal latches and registers are set to zero on the rising edge of this signal.
Output drivers are turned off when this input is low.
CC
OE
S
CLK
Serial clock input. Data is loaded into the part on the rising edge of S
. Data is shifted out of DATA
on the falling
CLK
OUT
9.
edge of S
.
CLK
CS
Active high chip select input. When CS is high, the part is enabled to receive a new serial input word. The high-to-low
transition of CS loads the new 20-bit word into the DAC registers and updates the output.
10.
ST
Status output. This is an open drain output and goes low when the coil output buffers (C1+, C1–, C2+, C2–, COM) have
been disabled. The coil outputs may be disabled due to shorted outputs, over-temperature conditions, power-on reset,
or by the output enable (OE) pin. Multiple status outputs , ST, may be wire OR’ed together.
11.
12.
13.
14.
15.
16.
D
Ground for V supply. Connect to Pins 3 and 13.
CC
GND
A
GND
Ground for V supply. Connect to Pins 3 and 12.
BB
COM
C2–
C2+
Output drive for biased coils. This output will be 1/2 of V
Negative output connection to the TAN coil of meter #2.
Positive output connection to the TAN coil of meter #2.
.
BB
3
1999 Sep 20
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
Table 2. SA5777A Pin Descriptions for the D Package (Small Outline)
Pin #
1.
Name
C1–
C1+
NC
Function
Negative output connection to the TAN coil of meter #1.
2.
Positive output connection to the TAN coil of meter #1.
3.
No connect
No connect
No connect
4.
NC
5.
NC
6.
A
GND
Ground for V supply. Pins 6, 20 and 23 should be connected on the circuit board.
BB
7.
V
BB
Analog supply. Nominally 13.5 V.
DATA
Serial data output. Output of the internal shift register. When a new data word is shifted in, the old word is shifted out
the DATA pin. DATA output is always active.
OUT
8.
9.
OUT
OUT
DATA
Serial data input. A new data word is serially shifted into the part on the rising edge of S . The data is shifted in MSB
CLK
IN
first, gauge 1 first.
10.
11.
12.
13.
14.
NC
NC
NC
No connect
No connect
No connect
V
CC
5 V logic supply. The internal latches and registers are set to zero on the rising edge of this signal.
Output drivers are turned off when this input is low.
OE
S
Serial clock input. Data is loaded into the part on the rising edge of S
. Data is shifted out of DATA
on the falling
CLK
CLK
OUT
15.
16.
edge of S
.
CLK
CS
Active high chip select input. When CS is high, the part is enabled to receive a new serial input word. The high-to-low
transition of CS loads the new 20-bit word into the DAC registers and updates the output.
17.
18.
NC
NC
ST
No connect
No connect
Status output. This is an open drain output and goes low when the coil output buffers (C1+, C1–, C2+, C2–, COM) have
been disabled. The coil outputs may be disabled due to shorted outputs, over-temperature conditions, power-on reset,
or by the output enable (OE) pin. Multiple status outputs , ST, may be wire OR’ed together.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
D
Ground for V supply. Connect to Pins 6 and 23.
GND
CC
NC
No connect
No connect
NC
A
GND
Ground for V supply. Connect to Pins 6 and 20.
BB
COM
Output drive for biased coils. This output will be 1/2 of V
No connect
.
BB
NC
NC
No connect
C2–
C2+
Negative output connection to the TAN coil of meter #2.
Positive output connection to the TAN coil of meter #2.
ABSOLUTE MAXIMUM RATINGS
SYMBOL
PARAMETER
RATING
-1 to +23
-1 to +6
-1 to +6
±0.5
UNIT
V
V
V
Analog supply
Digital supply
V
V
V
V
BB
CC
IN
Digital input voltage, Data In, OE, CS, S
Ground difference
CLK
D
to A
GND
GND
°C
°C
T
Ambient operating temperature
Junction temperature
–40 to +85
150
A
T
T
J
°C
mW
Storage temperature
–65 to +150
1500
STG
1
P
Power dissipation (T = 25°C) N, D packages
D
A
°C/W
θ
DIP and SO packages
90
JA
NOTE:
1. For power dissipation ratings in still air, derate above 25°C at the following rates:
N and D packages at 12mW/°C
4
1999 Sep 20
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
DC ELECTRICAL CHARACTERISTICS
V
BB
= 7.5 to 18 V; V = 4.5 to 5.5 V; T = –40 to +85°C.
CC A
LIMITS
TYP
SYMBOL
PARAMETER
TEST CONDITIONS
UNIT
MAX
MIN
V
Analog supply voltage
Analog supply current
7.5
18
30
V
BB
IGN
CC
V
V
R
= 18 V no load
= 18 V with load
IGN
BB
C1
I
mA
mA
= R = R
235
1.0
C2
LMIN
I
Logic supply current
Output high voltage
Output low voltage
V
CC
= 5.5 V
V
OH
V
OL
V
OL
Data out I = 800 µA
V
– 0.8
OH
CC
Data out I = 1.5 mA
0.4
0.8
25
V
V
OL
Status
Status
ST, I = 2.5 mA
OL
I
ST, VO (ST) = V
µA
OH
CC
V
V
Input high voltage
Input low voltage
Input high current
Input low current
CS, S
CS, S
, DATA , OE
0.7 x V
CC
V
IH
IL
CLK
CLK
IN
, DATA , OE
0.3 x V
V
IN
CC
I
IH
I
IL
CS, S
CS, S
, DATA , V = 0.7 x V
1
1
µA
CLK
IN
IN
CC
CC
, DATA , V = 0.3 x V
µA
CLK
IN
IN
2
A
CC
Output function accuracy
R
= R = R
LMIN
±1
Degree
C1
C2
C1+, C1–, C2+, C2–, COM
I
I
V
BB
V
BB
V
BB
V
BB
= V
= V
= V
= V
85
43
85
43
500
300
500
300
mA
mA
mA
mA
SINK
BB (MAX)
BB (MIN)
BB (MAX)
BB (MIN)
I
Output shut-down current
SD
SOURCE
V
= V
BB (MAX)
BB
L
1
V
Differential coil drive voltage
Minimum load resistance
0.7 x V
0.8 x V
BB
V
DRIVE
BB
R = R
L (MIN)
T = 85°C
215
171
138
Ω
Ω
Ω
A
T = 25°C
R
A
LMIN
BIAS
T = –40°C
A
IOB (Source or Sink)
R = R
3
V
Bias voltage
0.475 x V
0.525 x V
V
BB
BB
L
L (MIN)
NOTE:
1. V
is the maximum voltage that is applied across the coil, it is equal to (C1+) – (C1–) or (C2+) – (C2–).
DRIVE
2. In reference to nominal values in Figure 4. (Based on 7+ bit DAC).
(C )) – (C–)
VBB – VBIAS
Output Angle (0) + tan–1
3.
ƪ
ƫ
AC ELECTRICAL CHARACTERISTICS
V
DD
= 7.5 to 18 V; V = 4.5 to 5.5 V; T = –40 to +85°C
CC
A
LIMITS
TYP
SYMBOL
PARAMETER
TEST CONDITIONS
UNIT
MIN
MAX
FS
TS
TS
Input frequency
1.60
MHz
ns
CLK
S
CLK
S
CLK
high time
low time
175
175
CLKH
CLKL
V
CC
= 5.5 V
ns
TRO
TFO
TSU
THI
Output rise time DO
Output fall time DO
DI set-up time
0.75 to V –1.2 V, C = 90 pF
75
75
ns
CC
L
V
CC
–1.2 V to 0.75, C = 90 pF
ns
L
75
75
75
75
ns
DI hold time
ns
T
CSH
T
CSL
Time before first S
rising edge
CLK
ns
Time after last S
falling edge
ns
CLK
5
1999 Sep 20
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
maintain the meter accuracy at this maximum deflection. The 0.5 x
FUNCTIONAL DESCRIPTION
V
BB
bias coil voltage is obtained by connecting the bias coils of the
The SA5777A dual air-core gauge driver logic Block Diagram shows
the two 10-bit input shift registers and two 9-bit parallel latches, and
two 7+-bit DACs. The MSB is a dummy bit required for compatibility
with the SA5775A. The DACs generate output voltages that are
offset within the supply rails to give the output buffers enough
headroom to operate. With a 14 V supply, the typical output swing is
from 1 V to 11.5 V. The MUX generates the two required quadrants
by switching the 56° data from the DAC to the appropriate output
buffer. The output buffers provide the necessary current to drive the
air-core gauge. The output buffers are always connected to the
coils and can sink and source sufficient current so that inductive
kickback is eliminated during normal operation.
two meters in series across V . This gives bias stability over
BB
temperature. The internal bias generator is used to offset any
inaccuracies due to meter mismatches. This circuit receives
commands via an internal serial data interface port which is SPI
compatible. These parts can be serially cascaded with other
SA5777A ICs and/or SA5775A ICs to interface signals in multi-chip
systems. The SA5777A has a typical resolution of 0.35° over a full
scale deflection of approximately 112° and is guaranteed to be
monotonic. The input data is directly proportional to the displayed
angle in degrees (Figure NO TAG). Input code 0 gives an output
angle of 0°, code 319 (decimal) will generate a full scale output of
112.15°. Codes higher than decimal 319 will not be loaded into the
DAC latches and will leave the coil output buffers unchanged.
However, codes greater than 319 can be shifted through the
SA5777A intact if other parts are cascaded. The SA5777A is
capable of sourcing and sinking up to 100mA per differential driver
to control either one or two air-core gauge displays directly.
The primary function of the SA5777A IC is to generate the transfer
function that maps an input code into the correct voltages for linearly
controlling the coils of an air-core gauge display (Figure 3). The
SA5777A has been implemented using the tangent drive algorithm.
Therefore, one coil on each meter will be driven with an output
approximating the tangent function, the other coils will be biased at
On-chip overcurrent and thermal shut-down logic prevents the chip
from overheating due to high current fault conditions. When a
shut-down condition is detected, the protection circuit disables the
coil output buffers (i.e., C1+, C1–, C2+, C2–, COM). The coil output
buffers remain in this condition until the first falling edge of CS that
occurs after the die temperature has decreased to about 140°C or
the overcurrent condition has been removed. During shut-down, the
digital portion of this IC continues to operate normally.
1/2 V . The internal DAC is designed to operate over a 7+ bit (56°)
BB
data range. An extended range can be achieved by changing the
relationship between the bias coil and the driver coil. As the current
through the bias coil is reduced, the full scale deflection is
increased. Theoretically, this deflection could approach 180°, but
practical limitations of accuracy, resolution, and torque restrict the
full scale range to approximately 112° (Figure 4). This full scale
range corresponds to a bias coil voltage of 0.5 x V and a full scale
BB
tangent voltage of 0.744 x V . The DAC has been tailored to
BB
14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
31
63
95
127
159
191
223
255
287
319
–2.00
–4.00
INPUT CODE
–6.00
–8.00
–10.00
–12.00
–14.00
SL00462
Figure 3. Typical output voltage vs input code (V = 14 V)
BB
6
1999 Sep 20
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
ASSUMING CODE 0 IS 0°:
0.5 x V
BB
CODE
0
POSITION
–56.097
–45.194
–33.940
–22.685
–11.430
–0.176
31
63
95
–56°
+56°
127
159
191
223
255
287
319
11.079
22.333
–0.744 x V
0.744 x V
BB
BB
TOTAL SPAN = 112.15°
33.588
STEP SIZE = 0.35°
44.843
56.097
IDEAL ANGLE(DEGREE)=CODE/319*2* ArcTan (0.744/0.5)–ArcTan(0.744/0.5)
SL00463
Figure 4. Total span
120
100
80
60
40
20
0
0
15
31
41
63
79
95
111
127
143
159
175
191
207
223
239
255
271
287
303
319
INPUT CODE
SL00464
Figure 5. Meter position (degrees) vs input code
7
1999 Sep 20
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
CS
20 S
CYCLES
CLK
FS
CLK
T
CSH
TS
CLKL
1
2
19
20
TS
D0
CLKH
S
CLK
TC
SL
80%
20%
DATA
D19
D18
D1
IN
THI
TSU
D19*
D18*
D1*
D0*
DATA
OUT
TFO
TRO
GAUGE 2
GAUGE 1
D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15 D16 D17 D18 D19
LSB
MSB LSB
MSB
SL00465
*DO IS THE PREVIOUSLY LOADED DATA WORD
Figure 6. Serial interface timing
Serial Interface
The SA5777A is controlled through a serial interface with the following control functions (reference Figure 6):
S
CLK
Serial input clock. When CS is high, the rising edge of S
shifts a new data bit into the SA5777A and the falling edge shifts
CLK
the data out of DATA
.
OUT
CS
Active high chip select. Enables the SA5777A to receive serial input data. The falling edge of CS loads a new 20-bit data word
into the internal DAC registers which updates the tangent coil output buffers (C1+, C1–, C2+, C2–).
DATA
DATA
Serial data input. The data at this pin is shifted into the internal shift register on the rising edge of S
first, gauge 1 first.
. Data is shifted in MSB
CLK
IN
Serial data output. This pin is the output of the internal shift register. The data output on this pin is the input data from DATA
pin delayed by 20 clock cycles. This pin can be used to cascade several SA5777As with one CS line to load all of the
SA5777As concurrently.
OUT
IN
4. Due to excessive power dissipation (i.e., thermal shut-down).
The die temperature must go below 140°C before a falling edge
on the CS pin will clear this fault condition and allow the coil
outputs to go active.
Power Moding
The SA5777A has a power-on reset capability. On the rising edge
of V , the internal latches and registers are set to zero and the coil
CC
output buffers (C1+, C1–, C2+, C2–, COM) are disabled.
Coil Output Buffer Control
The coil buffers (C1+, C1–, C2+, C2–, COM) are disabled:
Application Notes
The air-core gauge is constructed of two coils would on a cavity at
90° to each other. Inside the cavity there is a disk which is
magnetized on its diameter. The currents through the coils generate
a resultant magnetic vector that causes the magnetic disc to move
until the magnetic fields are aligned. If the ratio of the currents in the
two coils follows the tangent function, then the transfer characteristic
relating the input data to output angle is linear.
1. With the rising edge of V (power-on reset).
CC
2. When OE is taken low or held low. The data registers for the
outputs can still be updated while OE is low. When OE is taken
high, the current output data value is displayed. A falling edge
on CS will be required to activate the outputs if a fault condition
has occurred prior to the OE going high.
Maximum current is when output is at zero and full scale degrees,
3. Due to an overcurrent condition on either of the coil output
buffers. The coil output buffers will be enabled after the next CS
high-to-low transition; assuming OE is high. If the overcurrent
condition has not been removed, the outputs will immediately
return to their disabled condition. The ST pin will indicate status
of the coil outputs.
T = –40°C, and R = 180.
A
L
Copper wire has a typical temperature coefficient of 0.4%/C
8
1999 Sep 20
Philips Semiconductors
Product specification
Dual air–core gauge driver
SA5777A
DIP16: plastic dual in-line package; 16 leads (300 mil)
SOT38-4
9
1999 Sep 20
Philips Semiconductors
Product specification
Dual air–core gauge driver
SA5777A
SO28: plastic small outline package; 28 leads; body width 7.5mm
SOT136-1
10
1999 Sep 20
Philips Semiconductors
Product specification
Dual air–core gauge driver
SA5777A
NOTES
11
1999 Sep 20
Philips Semiconductors
Product specification
Dual air–core gauge driver
SA5777A
Data sheet status
[1]
Data sheet
status
Product
status
Definition
Objective
specification
Development
This data sheet contains the design target or goal specifications for product development.
Specification may change in any manner without notice.
Preliminary
specification
Qualification
This data sheet contains preliminary data, and supplementary data will be published at a later date.
Philips Semiconductors reserves the right to make changes at any time without notice in order to
improve design and supply the best possible product.
Product
specification
Production
This data sheet contains final specifications. Philips Semiconductors reserves the right to make
changes at any time without notice in order to improve design and supply the best possible product.
[1] Please consult the most recently issued datasheet before initiating or completing a design.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Righttomakechanges—PhilipsSemiconductorsreservestherighttomakechanges, withoutnotice, intheproducts, includingcircuits,standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.
Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Copyright Philips Electronics North America Corporation 1999
All rights reserved. Printed in U.S.A.
Sunnyvale, California 94088–3409
Telephone 800-234-7381
Date of release: 09-99
Document order number:
9397 750 06444
Philips
Semiconductors
相关型号：
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