INTEGRATED CIRCUITS
SA5777A
Dual air–core gauge driver
Product specification
Supersedes data of 1997 Feb 24
1999 Sep 20
Philips
Semiconductors
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
DESCRIPTION
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.
PIN CONFIGURATION
N Package
C1–
C1+
A
GND
V
BB
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
C2+
C2-
COM
A
GND
D
GND
ST
CS
S
CLK
FEATURES
DATA
OUT
DATA
IN
V
CC
OE
•
10-Bit resolution (0.35 degrees)
•
Exceptional accuracy (0.5 degrees, typical)
•
High-torque capability
•
Active differential drivers eliminate back-EMF issues
•
No RFI/EMI generation issues
•
Simple serial interface
•
Simple cascading capability for multiple meters
•
Internal fault protection
•
Only one external component required (bypass capacitor)
APPLICATION
D Package
C1– 1
C1+ 2
NC 3
NC 4
NC 5
A
GND
6
28
27
26
25
24
23
22
21
20
19
18
17
16
15
C2+
C2-
NC
NC
COM
A
GND
NC
NC
D
GND
ST
NC
NC
CS
S
CLK
•
Instrumentation utilizing air-core meters
V
BB
DATA
OUT
DATA
IN
7
8
9
NC 10
NC 11
NC 12
V
CC
13
OE 14
SL00460
Figure 1. Pin configuration
ORDERING INFORMATION
DESCRIPTION
16-Pin Plastic Dual In-Line Package (DIP)
28-Pin Plastic Small Outline Package (SO)
TEMPERATURE RANGE
-40 to +85
°
C
-40 to +85
°
C
ORDER CODE
SA5777AN
SA5777AD
DWG #
SOT38-4
SOT136-1
1999 Sep 20
2
853-1930 022368
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
BLOCK DIAGRAM
V
BB
OE
C2+
7 + – BIT
DAC
MUX
C2–
V
BB
V
BB
/2
8
7 + – BIT
DAC
MUX
COM
C1+
8
C1–
CS
V
CC
D
IN
S
CLK
9-BIT LATCH
9-BIT LATCH
FAULT
DETECTION
ST
10-BIT
SHIFT REGISTER
10-BIT
SHIFT REGISTER
D
OUT
SL00461
Figure 2. Block diagram
Table 1. SA5777A Pin Descriptions for the N Package (Dual In-Line)
Pin #
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
D
GND
A
GND
COM
C2–
C2+
Name
C1–
C1+
A
GND
V
BB
DATA
OUT
DATA
IN
V
CC
OE
S
CLK
CS
ST
Negative output connection to the TAN coil of meter #1.
Positive output connection to the TAN coil of meter #1.
Ground for V
BB
supply. Pins 3, 12 and 13 should be connected on the circuit board.
Analog supply. Nominally 13.5 V.
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
OUT
pin. DATA
OUT
output is always active.
Serial data input. A new data word is serially shifted into the part on the rising edge of S
CLK
. The data is shifted in MSB
first, gauge 1 first.
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.
Serial clock input. Data is loaded into the part on the rising edge of S
CLK
. Data is shifted out of DATA
OUT
on the falling
edge of S
CLK
.
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.
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.
Ground for V
CC
supply. Connect to Pins 3 and 13.
Ground for V
BB
supply. Connect to Pins 3 and 12.
Output drive for biased coils. This output will be 1/2 of V
BB
.
Negative output connection to the TAN coil of meter #2.
Positive output connection to the TAN coil of meter #2.
Function
1999 Sep 20
3
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
Table 2. SA5777A Pin Descriptions for the D Package (Small Outline)
Pin #
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
D
GND
NC
NC
A
GND
COM
NC
NC
C2–
C2+
Name
C1–
C1+
NC
NC
NC
A
GND
V
BB
DATA
OUT
DATA
IN
NC
NC
NC
V
CC
OE
S
CLK
CS
NC
NC
ST
Negative output connection to the TAN coil of meter #1.
Positive output connection to the TAN coil of meter #1.
No connect
No connect
No connect
Ground for V
BB
supply. Pins 6, 20 and 23 should be connected on the circuit board.
Analog supply. Nominally 13.5 V.
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
OUT
pin. DATA
OUT
output is always active.
Serial data input. A new data word is serially shifted into the part on the rising edge of S
CLK
. The data is shifted in MSB
first, gauge 1 first.
No connect
No connect
No connect
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.
Serial clock input. Data is loaded into the part on the rising edge of S
CLK
. Data is shifted out of DATA
OUT
on the falling
edge of S
CLK
.
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.
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.
Ground for V
CC
supply. Connect to Pins 6 and 23.
No connect
No connect
Ground for V
BB
supply. Connect to Pins 6 and 20.
Output drive for biased coils. This output will be 1/2 of V
BB
.
No connect
No connect
Negative output connection to the TAN coil of meter #2.
Positive output connection to the TAN coil of meter #2.
Function
ABSOLUTE MAXIMUM RATINGS
SYMBOL
V
BB
V
CC
V
IN
D
GND
to A
GND
T
A
T
J
T
STG
P
D
θ
JA
Analog supply
Digital supply
Digital input voltage, Data In, OE, CS, S
CLK
Ground difference
Ambient operating temperature
Junction temperature
Storage temperature
Power dissipation (T
A
= 25°C)
1
N, D packages
DIP and SO packages
PARAMETER
RATING
-1 to +23
-1 to +6
-1 to +6
±0.5
–40 to +85
150
–65 to +150
1500
90
UNIT
V
V
V
V
°
C
°
C
°
C
mW
°
C/W
NOTE:
1. For power dissipation ratings in still air, derate above 25°C at the following rates:
N and D packages at 12mW/°C
1999 Sep 20
4
Philips Semiconductors
Product specification
Dual air-core gauge driver
SA5777A
DC ELECTRICAL CHARACTERISTICS
V
BB
= 7.5 to 18 V; V
CC
= 4.5 to 5.5 V; T
A
= –40 to +85°C.
SYMBOL
V
BB
I
IGN
I
CC
V
OH
V
OL
V
OL
Status
I
OH
Status
V
IH
V
IL
I
IH
I
IL
A
CC
Input high voltage
Input low voltage
Input high current
Input low current
Output function
accuracy
2
PARAMETER
Analog supply voltage
Analog supply current
Logic supply current
Output high voltage
Output low voltage
V
IGN
= 18 V no load
V
BB
= 18 V with load
R
C1
= R
C2
= R
LMIN
V
CC
= 5.5 V
Data out I
OH
= 800
µA
Data out I
OL
= 1.5 mA
ST, I
OL
= 2.5 mA
ST, VO (ST) = V
CC
CS, S
CLK
, DATA
IN
, OE
CS, S
CLK
, DATA
IN
, OE
CS, S
CLK
, DATA
IN
, V
IN
= 0.7 x V
CC
CS, S
CLK
, DATA
IN
, V
IN
= 0.3 x V
CC
R
C1
= R
C2
= R
LMIN
C1+, C1–, C2+, C2–, COM
I
SINK
V
BB
= V
BB (MAX)
V
BB
= V
BB (MIN)
I
SOURCE
V
BB
= V
BB (MAX)
V
BB
= V
BB (MIN)
V
BB
= V
BB (MAX)
R
L
= R
L (MIN)
T
A
= 85°C
T
A
= 25°C
T
A
= –40°C
IOB (Source or Sink)
R
L
= R
L (MIN)
85
43
85
43
0.7 x V
BB
215
171
138
0.475 x V
BB
0.525 x V
BB
0.7 x V
CC
0.3 x V
CC
1
1
±1
500
300
500
300
0.8 x V
BB
V
CC
– 0.8
0.4
0.8
25
V
V
µA
V
V
µA
µA
Degree
mA
mA
mA
mA
V
Ω
Ω
Ω
V
TEST CONDITIONS
LIMITS
MIN
7.5
TYP
MAX
18
30
mA
235
1.0
mA
UNIT
V
I
SD
Output shut-down current
V
DRIVE
R
LMIN
V
BIAS
Differential coil drive voltage
1
Minimum load resistance
Bias voltage
3
NOTE:
1. V
DRIVE
is the maximum voltage that is applied across the coil, it is equal to (C1+) – (C1–) or (C2+) – (C2–).
2. In reference to nominal values in Figure 4. (Based on 7+ bit DAC).
3. Output Angle (0)
+
tan
–1
(C
))
– (C–)
V
BB
– V
BIAS
AC ELECTRICAL CHARACTERISTICS
V
DD
= 7.5 to 18 V; V
CC
= 4.5 to 5.5 V; T
A
= –40 to +85°C
SYMBOL
FS
CLK
TS
CLKH
TS
CLKL
TRO
TFO
TSU
THI
T
CSH
T
CSL
PARAMETER
Input frequency
S
CLK
high time
S
CLK
low time
Output rise time DO
Output fall time DO
DI set-up time
DI hold time
Time before first S
CLK
rising edge
Time after last S
CLK
falling edge
V
CC
= 5.5 V
0.75 to V
CC
–1.2 V, C
L
= 90 pF
V
CC
–1.2 V to 0.75, C
L
= 90 pF
75
75
75
75
175
175
75
75
TEST CONDITIONS
LIMITS
MIN
TYP
MAX
1.60
UNIT
MHz
ns
ns
ns
ns
ns
ns
ns
ns
1999 Sep 20
5