DATASHEET

ISL90840
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PROD
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Data Sheet
LE SU 95840
X
POSSIB
Quad Digitally Controlled Potentiometers (XDCP™)
November 14, 2006
FN8086.2
Low Noise, Low Power I2C® Bus, 256 Taps
Features
The ISL90840 integrates four digitally controlled
potentiometers (XDCP) on a monolithic CMOS integrated
circuit.
• Four potentiometers in one package
• 256 resistor taps - 0.4% resolution
• I2C serial interface
- Three address pins, up to eight devices/bus
The digitally controlled potentiometers are implemented with
a combination of resistor elements and CMOS switches. The
position of the wipers are controlled by the user through the
I2C bus interface. Each potentiometer has an associated
volatile Wiper Register (WR) that can be directly written to
and read by the user. The contents of the WR controls the
position of the wiper. When powered on the ISL90810’s
wiper will always commence at mid-scale (128 tap position).
- Write/Read capability
• Power-on preset to mid-scale (128 tap position)
• Wiper resistance: 70 typical @ 3.3V
• Standby current <5µA max
• Power supply: 2.7V to 5.5V
The DCPs can be used as three-terminal potentiometers or
as two-terminal variable resistors in a wide variety of
applications including control, parameter adjustments, and
signal processing.
• 50k, 10k total resistance
• 20 Ld TSSOP package
• Pb-free plus anneal available (RoHS compliant)
Pinout
ISL90840
(20 LD TSSOP)
TOP VIEW
RH3
1
20
RW0
RL3
2
19
RL0
RW3
3
18
RH0
A2
4
17
D.N.C.
SCL
5
16
VCC
SDA
6
15
A1
GND
7
14
A0
RW2
8
13
RH1
RL2
9
12
RL1
RH2
10
11
RW1
Ordering Information
PART NUMBER
PART MARKING
ISL90840UIV2027Z (Notes 1 and 2)
ISL90840UI27Z
ISL90840UIV2027
ISL90840UI27
RESIST-ANCE
OPTION
()
TEMP
RANGE
(°C)
50k
-40 to +85
PACKAGE
20 Ld TSSOP (Pb-free)
PKG. DWG #
MDP0044
50k
-40 to +85
20 Ld TSSOP
MDP0044
ISL90840UAV2027Z (Notes 1 and 2) ISL90840UA27Z
50k
-40 to +105
20 Ld TSSOP (Pb-free)
MDP0044
ISL90840WIV2027Z (Notes 1 and 2) ISL90840WI27Z
10k
-40 to +85
20 Ld TSSOP (Pb-free)
MDP0044
ISL90840WIV2027
10k
-40 to +85
20 Ld TSSOP
MDP0044
10k
-40 to +105
20 Ld TSSOP (Pb-free)
MDP0044
ISL90840WI27
ISL90840WAV2027Z (Notes 1 and 2) ISL90840WA27Z
NOTES:
1. Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are
MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
2. Add “T2” suffix for tape and reel.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) and XDCP are registered trademarks of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2005-2006. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
ISL90840
Functional Diagram
VCC
RH0
RH1
RH2
RH3
SCL
SDA
A0
I2C
INTERFACE
A1
A2
GND
RL0
RW0
RL1
RW1
RL2
RW2
RL3
RW3
Block Diagram
VCC
I2C INTERFACE
SDA
SCL
POWER-UP,
INTERFACE,
CONTROL
AND STATUS
LOGIC
WR3
DCP3
RH3
RW3
RL3
WR2
DCP2
RH2
RW2
RL2
WR1
DCP1
RH1
RW1
RL1
WR0
DCP0
RH0
RW0
RL0
A2
A1
A0
GND
2
FN8086.2
November 14, 2006
ISL90840
Pin Descriptions
TSSOP PIN
SYMBOL
1
RH3
“High” terminal of DCP3
2
RL3
“Low” terminal of DCP3
3
RW3
“Wiper” terminal of DCP3
4
A2
5
SCL
I2C interface clock
6
SDA
Serial data I/O for the I2C interface
7
GND
Device ground pin
8
RW2
“Wiper” terminal of DCP2
9
RL2
“Low” terminal of DCP2
10
RH2
“High” terminal of DCP2
11
RW1
“Wiper” terminal of DCP1
12
RL1
“Low” terminal of DCP1
13
RH1
“High” terminal of DCP1
14
A0
Device address for the I2C interface
15
A1
Device address for the I2C interface
16
VCC
17
D.N.C.
18
RH0
“High” terminal of DCP0
19
RL0
“Low” terminal of DCP0
20
RW0
“Wiper” terminal of DCP0
3
DESCRIPTION
Device address for the I2C interface
Power supply pin
Do not connect
FN8086.2
November 14, 2006
ISL90840
Absolute Maximum Ratings
Thermal Information
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Voltage at Any Digital Interface Pin
With Respect to VSS . . . . . . . . . . . . . . . . . . . . -0.3V to VCC+0.3V
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V
Voltage at Any DCP Pin
With Respect to VSS . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC
Lead Temperature (Soldering, 10s) . . . . . . . . . . . . . . . . . . . . +300°C
IW (10s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±6mA
Latchup . . . . . . . . . . . . . . . . . . . . . . . . . Class II, Level A @ +105°C
ESD
HBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5kV
Thermal Resistance (Typical, Note 3)
JA (°C/W)
20 Ld TSSOP Package . . . . . . . . . . . . . . . . . . . . . .
90
Maximum Junction Temperature (Plastic Package). . . . . . . . +150°C
Recommended Operating Conditions
Industrial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +85°C
Automotive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +105°C
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7V to 5.5V
Power Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5mW
Wiper Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±3.0mA
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
3. JA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
Analog Specifications
SYMBOL
RTOTAL
Over recommended operating conditions unless otherwise stated.
PARAMETER
RH to RL resistance
TEST CONDITIONS
CH/CL/CW
ILkgDCP
Wiper resistance
MAX
UNIT
10
k
U option
50
k
-20
VCC = 3.3V @ +25°C,
wiper current = VCC/RTOTAL
70
Potentiometer capacitance (Note 18)
Leakage on DCP pins (Note 18)
TYP
(NOTE 4)
W option
RH to RL resistance tolerance
RW
MIN
+20
%
200

10/10/25
Voltage at pin from GND to VCC
0.1
pF
1
µA
-1
1
LSB
(Note 5)
-0.5
0.5
LSB
(Note 5)
LSB
(Note 5)
VOLTAGE DIVIDER MODE (0V @ RLi; VCC @ RHi; measured at RWi, unloaded; i = 0, 1, 2, or 3)
INL
(Note 9)
Integral non-linearity
DNL
(Note 8)
Differential non-linearity
Monotonic over all tap positions
ZSerror
(Note 6)
Zero-scale error
W option
0
1
7
U option
0
0.5
2
FSerror
(Note 7)
Full-scale error
W option
-7
-1
0
U option
-2
-1
0
VMATCH
(Note 10)
DCP to DCP matching
Any two DCPs at same tap position, same
voltage at all RH terminals, and same voltage
at all RL terminals
-2
TCV
(Note 11)
Ratiometric temperature coefficient
DCP register set to 80 hex
2
±4
LSB
(Note 5)
LSB
(Note 5)
ppm/°C
RESISTOR MODE (Measurements between RWi and RLi with RHi not connected, or between RWi and RHi with RLi not connected. i = 0, 1, 2 or 3)
RINL
(Note 15)
Integral non-linearity
RDNL
(Note 14)
Differential non-linearity
Roffset
(Note 13)
Offset
RMATCH
(Note 16)
DCP to DCP matching
4
DCP register set between 20 hex and FF
hex; monotonic over all tap positions
-1
1
MI
(Note 12)
-0.5
0.5
MI
(Note 12)
MI
(Note 12)
W option
0
1
7
U option
0
0.5
2
Any two DCPs at the same tap position with
the same terminal voltages
-2
2
MI
(Note 12)
FN8086.2
November 14, 2006
ISL90840
Analog Specifications
SYMBOL
TCR
(Note 17)
Over recommended operating conditions unless otherwise stated. (Continued)
PARAMETER
Resistance temperature coefficient
TEST CONDITIONS
MIN
DCP register set between 20 hex and FF hex
TYP
(NOTE 4)
MAX
±45
UNIT
ppm/°C
Operating Specifications Over the recommended operating conditions unless otherwise specified.
SYMBOL
ICC1
ISB
ILkgDig
tDCP
(Note 18)
PARAMETER
TEST CONDITIONS
MIN
TYP
(NOTE 4)
= 400kHz; SDA = Open; (for I2C, active,
MAX
UNIT
1
mA
VCC supply current (volatile
write/read)
fSCL
read and write states)
VCC current (standby)
VCC = +5.5V, I2C Interface in Standby State,
Temperature range from -40°C to 85°C
2
5
µA
VCC = +5.5V, I2C Interface in Standby State,
Temperature range from -40°C to 105°C
2
8
µA
VCC = +3.6V, I2C Interface in Standby State,
Temperature range from -40°C to 85°C
0.8
2
µA
VCC = +3.6V, I2C Interface in Standby State,
Temperature range from -40°C to 105°C
0.8
5
µA
10
µA
Leakage current, at pins A0, A1, A2,
SDA, and SCL
Voltage at pin from GND to VCC
DCP wiper response time
SCL falling edge of last bit of DCP data byte
to wiper change
-10
1
µs
SERIAL INTERFACE SPECS
VIL
A2, A1, A0, SDA, and SCL input buffer
LOW voltage
-0.3
0.3*VCC
V
VIH
A2, A1, A0, SDA, and SCL input buffer
HIGH voltage
0.7*VCC
VCC+0.3
V
Hysteresis
(Note 18)
SDA and SCL input buffer hysteresis
0.05*
VCC
VOL
(Note 18)
SDA output buffer LOW voltage,
sinking 4mA
Cpin
(Note 18)
fSCL
0
V
0.4
V
A2, A1, A0, SDA, and SCL pin
capacitance
10
pF
SCL frequency
400
kHz
tIN
(Note 18)
Pulse width suppression time at SDA
and SCL inputs
Any pulse narrower than the max spec is
suppressed
50
ns
tAA
(Note 18)
SCL falling edge to SDA output data
valid
SCL falling edge crossing 30% of VCC, until
SDA exits the 30% to 70% of VCC window
900
ns
tBUF
(Note 18)
Time the bus must be free before the
start of a new transmission
SDA crossing 70% of VCC during a STOP
condition, to SDA crossing 70% of VCC
during the following START condition
1300
ns
tLOW
Clock LOW time
Measured at the 30% of VCC crossing
1300
ns
tHIGH
Clock HIGH time
Measured at the 70% of VCC crossing
600
ns
tSU:STA
START condition setup time
SCL rising edge to SDA falling edge; both
crossing 70% of VCC
600
ns
tHD:STA
START condition hold time
From SDA falling edge crossing 30% of VCC
to SCL falling edge crossing 70% of VCC
600
ns
tSU:DAT
Input data setup time
From SDA exiting the 30% to 70% of VCC
window, to SCL rising edge crossing 30% of
VCC
100
ns
tHD:DAT
Input data hold time
From SCL rising edge crossing 70% of VCC
to SDA entering the 30% to 70% of VCC
window
0
ns
5
FN8086.2
November 14, 2006
ISL90840
Operating Specifications Over the recommended operating conditions unless otherwise specified. (Continued)
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
TYP
(NOTE 4)
MAX
UNIT
tSU:STO
STOP condition setup time
From SCL rising edge crossing 70% of VCC,
to SDA rising edge crossing 30% of VCC
600
ns
tHD:STO
STOP condition hod time for read, or
volatile only write
From SDA rising edge to SCL falling edge;
both crossing 70% of VCC
600
ns
tDH
(Note 18)
Output data hold time
From SCL falling edge crossing 30% of VCC,
until SDA enters the 30% to 70% of VCC
window
0
ns
tR
(Note 18)
SDA and SCL rise time
From 30% to 70% of VCC
20 +
0.1 * Cb
250
ns
tF
(Note 18)
SDA and SCL fall time
From 70% to 30% of VCC
20 +
0.1 * Cb
250
ns
Cb
(Note 18)
Capacitive loading of SDA or SCL
Total on-chip and off-chip
10
400
pF
Rpu
(Note 18)
SDA and SCL bus pull-up resistor off- Maximum is determined by tR and tF
chip
For Cb = 400pF, max is about 2~2.5k.
For Cb = 40pF, max is about 15~20k
1
k
tSU:A
A2, A1 and A0 setup time
Before START condition
600
ns
tHD:A
A2, A1 and A0 hold time
After STOP condition
600
ns
NOTES:
4. Typical values are for TA = 25°C and 3.3V supply voltage.
5. LSB: [V(RW)255 – V(RW)0]/255. V(RW)255 and V(RW)0 are V(RW) for the DCP register set to FF hex and 00 hex respectively. LSB is the
incremental voltage when changing from one tap to an adjacent tap.
6. ZS error = V(RW)0/LSB.
7. FS error = [V(RW)255 – VCC]/LSB.
8. DNL = [V(RW)i – V(RW)i-1]/LSB-1, for i = 1 to 255. i is the DCP register setting.
9. INL = [V(RW)i – i • LSB – V(RW)]/LSB for i = 1 to 255.
10. VMATCH = [V(RWx)i – V(RWy)i]/LSB, for i = 0 to 255, x = 0 to 3 and y = 0 to 3.
Max  V  RW  i  – Min  V  RW  i 
10 6
11. TC V = ----------------------------------------------------------------------------------------------  ----------------- for i = 16 to 240 decimal, T = -40°C to +105°C. Max( ) is the maximum value of the wiper
 Max  V  RW  i  + Min  V  RW  i    2 145°C voltage and Min ( ) is the minimum value of the wiper voltage over the temperature range.
12. MI = |R255 – R0|/255. R255 and R0 are the measured resistances for the DCP register set to FF hex and 00 hex respectively.
13. Roffset = R0/MI, when measuring between RW and RL.
Roffset = R255/MI, when measuring between RW and RH.
14. RDNL = (Ri – Ri-1)/MI-1, for i = 32 to 255.
15. RINL = [Ri – (MI • i) – R0]/MI, for i = 32 to 255.
16. RMATCH = (Ri,x – Ri,y)/MI, for i = 0 to 255, x = 0 to 3 and y = 0 to 3.
6
 Max  Ri  – Min  Ri  
10
17. TC R = ----------------------------------------------------------------  ----------------- for i = 32 to 255, T = -40°C to +105°C. Max( ) is the maximum value of the resistance and Min ( ) is
 Max  Ri  + Min  Ri    2 145°C the minimum value of the resistance over the temperature range.
18. This parameter is not 100% tested
6
FN8086.2
November 14, 2006
ISL90840
SDA vs SCL Timing
tF
tHIGH
SCL
tLOW
tR
tSU:DAT
tSU:STA
tHD:DAT
tSU:STO
tHD:STA
SDA
(INPUT TIMING)
tAA
tDH
tBUF
SDA
(OUTPUT TIMING)
A0, A1, and A2 Pin Timing
STOP
START
SCL
CLK 1
SDA IN
tSU:A
tHD:A
A0, A1, OR A2
Typical Performance Curves
1.8
160
VCC=2.7, T=+85°C
VCC=2.7, T=-40°C
1.6
VCC=2.7, T=+25°C
120
1.4
STANDBY ICC (µA)
WIPER RESISTANCE ()
140
100
80
60
40
1.2
-40°C
1
0.8
+85°C
0.6
0.4
20
VCC=5.5, T=-40°C
0
0
50
VCC= 5.5, T=+85°C
VCC=5.5, T=+25°C
100
150
200
TAP POSITION (DECIMAL)
FIGURE 1. WIPER RESISTANCE vs TAP POSITION
[I(RW) = VCC / RTOTAL] FOR 50k (U)
7
250
0.2
0
2.7
+25°C
3.2
3.7
4.2
4.7
5.2
VCC (V)
FIGURE 2. STANDBY ICC vs VCC
FN8086.2
November 14, 2006
ISL90840
Typical Performance Curves
0.2
0.3
VCC=5.5, T=-40°C
0.15
(Continued)
VCC=2.7, T=-40°C
VCC=2.7, T=-40°C
VCC=2.7, T=+25°C
VCC=5.5, T=-40°C
0.2
VCC=5.5, T=+85°C
0.1
0.1
INL (LSB)
DNL (LSB)
0.05
0
-0.05
0
VCC=2.7, T=+25°C
-0.1
-0.1
VCC=5.5, T=+25°C
-0.15
-0.2
VCC=5.5, T=+85°C
VCC=2.7, T=+85°C
VCC=2.7, T=+85°C
0.3
-0.2
0
50
100
150
200
0
250
50
0.4
0
0.35
-0.2
0.3
2.7V
0.25
0.15
-40
0
20
-0.6
VCC=2.7V
-0.8
40
60
-1
-40
80
-20
20
0
40
60
80
TEMPERATURE (°C)
FIGURE 5. ZSerror vs TEMPERATURE FOR 50k (W)
FIGURE 6. FSerror vs TEMPERATURE FOR 50k (W)
0.3
0.5
VCC=2.7, T=+25°C
VCC=2.7, T=+25°C
VCC=5.5, T=+25°C
0.3
VCC=5.5, T=-40°C
0.1
INL (LSB)
DNL (LSB)
250
VCC=5.5V
TEMPERATURE (°C)
0.2
200
-0.4
5.5V
-20
150
FIGURE 4. INL vs TAP POSITION IN VOLTAGE DIVIDER
MODE FOR 10k (W)
FSerror (LSB)
ZSerror (LSB)
FIGURE 3. DNL vs TAP POSITION IN VOLTAGE DIVIDER
MODE FOR 10k (W)
0.2
100
TAP POSITION (DECIMAL)
TAP POSITION (DECIMAL)
0
VCC=5.5, T=+85°C
0.1
VCC=2.7, T=+85°C
-0.1
-0.1
VCC=5.5, T=+85°C
-0.2
-0.3
32
VCC=2.7, T=-40°C
VCC=2.7, T=+85°C
-0.3
VCC=5.5, T=-40°C
82
132
182
232
TAP POSITION (DECIMAL)
FIGURE 7. DNL vs TAP POSITION IN RHEOSTAT MODE FOR
50k (U)
8
-0.5
32
VCC=2.7,
T=-40°C
VCC=5.5, T=+25°C
82
132
182
232
TAP POSITION (DECIMAL)
FIGURE 8. INL vs TAP POSITION IN RHEOSTAT MODE FOR
50k (U)
FN8086.2
November 14, 2006
ISL90840
Typical Performance Curves
(Continued)
20
1
10
0.5
2.7V
0
5.5V
TC (ppm/°C)
END TO END RTOTAL CHANGE (%)
1.5
-0.5
0
-10
-1
-1.5
-40
-20
20
0
40
60
80
-20
32
82
132
182
232
TAP POSITION (DECIMAL)
TEMPERATURE (°C)
FIGURE 10. TC FOR VOLTAGE DIVIDER MODE IN ppm FOR
50k (W)
FIGURE 9. END TO END RTOTAL % CHANGE vs
TEMPERATURE FOR 50k (W)
35
TC (ppm/°C)
25
INPUT
15
5
OUTPUT
-5
-15
-25
32
82
132
182
232
TAP POSITION = MID POINT
RTOTAL=9.4k
TAP POSITION (DECIMAL)
FIGURE 11. TC FOR RHEOSTAT MODE IN ppm FOR 50k (W)
SIGNAL AT WIPER (WIPER UNLOADED)
FIGURE 12. FREQUENCY RESPONSE (2.2MHz)
SCL
SIGNAL AT WIPER
(WIPER UPLOADED
MOVEMENT FROM
ffh TO 00h
WIPER MOVEMENT MID POINT
FROM 80h TO 7fh
FIGURE 13. MIDSCALE GLITCH, CODE 80h TO 7Fh (WIPER 0)
9
FIGURE 14. LARGE SIGNAL SETTLING TIME
FN8086.2
November 14, 2006
Principles of Operation
The ISL90840 is an integrated circuit incorporating four
DCPs with their associated registers, and an I2C serial
interface providing direct communication between a host
and the potentiometers.
DCP Description
Each DCP is implemented with a combination of resistor
elements and CMOS switches. The physical ends of each
DCP are equivalent to the fixed terminals of a mechanical
potentiometer (RH and RL pins). The RW pin of each DCP is
connected to intermediate nodes, and is equivalent to the
wiper terminal of a mechanical potentiometer. The position
of the wiper terminal within the DCP is controlled by an 8-bit
volatile Wiper Register (WR). Each DCP has its own WR.
When the WR of a DCP contains all zeroes (WR[7:0]: 00h),
its wiper terminal (RW) is closest to its “Low” terminal (RL).
When the WR of a DCP contains all ones (WR[7:0]: FFh), its
wiper terminal (RW) is closest to its “High” terminal (RH). As
the value of the WR increases from all zeroes (0 decimal) to
all ones (255 decimal), the wiper moves monotonically from
the position closest to RL to the closest to RH. At the same
time, the resistance between RW and RL increases
monotonically, while the resistance between RH and RW
decreases monotonically.
While the ISL90840 is being powered up, all four WRs are
reset to 80h (128 decimal), which locates RW roughly at the
center between RL and RH.
The WRs can be read or written to directly using the I2C
serial interface as described in the following sections. The
I2C interface Address Byte has to be set to 00h, 01h, 02h,
and 03h to access the WR of DCP0, DCP1, DCP2, and
DCP3 respectively
I2C Serial Interface
All I2C interface operations must begin with a START
condition, which is a HIGH to LOW transition of SDA while
SCL is HIGH. The ISL90840 continuously monitors the SDA
and SCL lines for the START condition and does not
respond to any command until this condition is met (See
Figure 15). A START condition is ignored during the powerup of the device.
All I2C interface operations must be terminated by a STOP
condition, which is a LOW to HIGH transition of SDA while
SCL is HIGH (See Figure 15). A STOP condition at the end
of a read operation, or at the end of a write operation places
the device in its standby mode.
An acknowledge (ACK) is a software convention used to
indicate a successful data transfer. The transmitting device,
either master or slave, releases the SDA bus after
transmitting eight bits. During the ninth clock cycle, the
receiver pulls the SDA line LOW to acknowledge the
reception of the eight bits of data (See Figure 16).
The ISL90840 responds with an ACK after recognition of a
START condition followed by a valid Identification Byte, and
once again after successful receipt of an Address Byte. The
ISL90840 also responds with an ACK after receiving a Data
Byte of a write operation. The master must respond with an
ACK after receiving a Data Byte of a read operation
A valid Identification Byte contains 0101 as the four MSBs,
and the following three bits matching the logic values
present at pins A2, A1, and A0. The LSB is the Read/Write
bit. Its value is “1” for a Read operation, and “0” for a Write
operation (See Table 1).
TABLE 1. IDENTIFICATION BYTE FORMAT
Logic values at pins A2, A1, and A0 respectively
0
(MSB)
1
0
1
A2
A1
A0
R/W
(LSB)
The ISL90840 supports a bidirectional bus oriented protocol.
The protocol defines any device that sends data onto the
bus as a transmitter and the receiving device as the receiver.
The device controlling the transfer is a master and the
device being controlled is the slave. The master always
initiates data transfers and provides the clock for both
transmit and receive operations. Therefore, the ISL90840
operates as a slave device in all applications.
All communication over the I2C interface is conducted by
sending the MSB of each byte of data first.
Protocol Conventions
Data states on the SDA line must change only during SCL
LOW periods. SDA state changes during SCL HIGH are
reserved for indicating START and STOP conditions (See
Figure 15). On power-up of the ISL90840 the SDA pin is in
the input mode.
10
FN8086.2
November 14, 2006
SCL
SDA
START
DATA
STABLE
DATA
CHANGE
DATA
STABLE
STOP
FIGURE 15. VALID DATA CHANGES, START, AND STOP CONDITIONS
SCL FROM
MASTER
1
8
SDA OUTPUT FROM
TRANSMITTER
9
HIGH IMPEDANCE
HIGH IMPEDANCE
SDA OUTPUT FROM
RECEIVER
START
ACK
FIGURE 16. ACKNOWLEDGE RESPONSE FROM RECEIVER
11
FN8086.2
November 14, 2006
WRITE
SIGNALS FROM
THE MASTER
SIGNAL AT SDA
S
T
A
R
T
IDENTIFICATION
BYTE
ADDRESS
BYTE
0 1 0 1 A2 A1 A0 0
0 0 0 0 0 0
SIGNALS FROM
THE ISL90840
S
T
O
P
DATA
BYTE
A
C
K
A
C
K
A
C
K
FIGURE 17. BYTE WRITE SEQUENCE
SIGNALS
FROM THE
MASTER
S
T
A
R
T
SIGNAL AT SDA
IDENTIFICATION
BYTE WITH
R/W=0
ADDRESS
BYTE
0 1 0 1 A2 A1 A0 0
A
C
K
S
A T
C O
K P
A
C
K
0 1 0 1 A2 A1 A0 1
0 0 0 0 0 0
A
C
K
SIGNALS FROM
THE SLAVE
S
T
A IDENTIFICATION
R
BYTE WITH
T
R/W=1
A
C
K
A
C
K
FIRST READ
DATA BYTE
LAST READ
DATA BYTE
FIGURE 18. READ SEQUENCE
Write Operation
Read Operation
A Write operation requires a START condition, followed by a
valid Identification Byte, a valid Address Byte, a Data Byte,
and a STOP condition. After each of the three bytes, the
ISL90840 responds with an ACK. At this time, the device
enters its standby state (See Figure 17).
A Read operation consist of a three byte instruction followed
by one or more Data Bytes (See Figure 18). The master
initiates the operation issuing the following sequence: a
START, the Identification byte with the R/W bit set to “0”, an
Address Byte, a second START, and a second Identification
byte with the R/W bit set to “1”. After each of the three bytes,
the ISL90840 responds with an ACK. Then the ISL90840
transmits Data Bytes as long as the master responds with an
ACK during the SCL cycle following the eighth bit of each
byte. The master terminates the read operation (issuing a
ACK and STOP condition) following the last bit of the last
Data Byte (See Figure 18).
The Data Bytes are from the registers indicated by an
internal pointer. This pointer initial value is determined by the
Address Byte in the Read operation instruction, and
increments by one during transmission of each Data Byte.
After reaching the memory location 03h, the pointer “rolls
over” to 00h, and the device continues to output data for
each ACK received.
12
FN8086.2
November 14, 2006
ISL90840
Thin Shrink Small Outline Package Family (TSSOP)
MDP0044
0.25 M C A B
D
THIN SHRINK SMALL OUTLINE PACKAGE FAMILY
A
SYMBOL 14 LD 16 LD 20 LD 24 LD 28 LD TOLERANCE
(N/2)+1
N
PIN #1 I.D.
E
E1
0.20 C B A
1
(N/2)
B
2X
N/2 LEAD TIPS
TOP VIEW
0.05
e
C
H
A
1.20
1.20
1.20
1.20
1.20
Max
A1
0.10
0.10
0.10
0.10
0.10
±0.05
A2
0.90
0.90
0.90
0.90
0.90
±0.05
b
0.25
0.25
0.25
0.25
0.25
+0.05/-0.06
c
0.15
0.15
0.15
0.15
0.15
+0.05/-0.06
D
5.00
5.00
6.50
7.80
9.70
±0.10
E
6.40
6.40
6.40
6.40
6.40
Basic
E1
4.40
4.40
4.40
4.40
4.40
±0.10
e
0.65
0.65
0.65
0.65
0.65
Basic
L
0.60
0.60
0.60
0.60
0.60
±0.15
L1
1.00
1.00
1.00
1.00
1.00
Reference
Rev. E 12/02
NOTES:
SEATING
PLANE
0.10 M C A B
b
0.10 C
N LEADS
SIDE VIEW
1. Dimension “D” does not include mold flash, protrusions or gate
burrs. Mold flash, protrusions or gate burrs shall not exceed
0.15mm per side.
2. Dimension “E1” does not include interlead flash or protrusions.
Interlead flash and protrusions shall not exceed 0.25mm per
side.
3. Dimensions “D” and “E1” are measured at dAtum Plane H.
SEE DETAIL “X”
c
4. Dimensioning and tolerancing per ASME Y14.5M-1994.
END VIEW
L1
A
A2
GAUGE
PLANE
0.25
L
A1
0° - 8°
DETAIL X
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13
FN8086.2
November 14, 2006