Advance Data Sheet
September 2001
LSP2908
8-Channel, High-Voltage Driver
Features
I
Eight amplifier channels in one package
I
Outputs from 298 V to +160 V per channel
I
Programmable output current limit (100
A to
500
A)
I
Variable voltage gain set by external resistors
Applications
I
Optical crosspoint switches
I
Optical microelectromechanical systems (MEMS)
components
Description
The LSP2908 eight-channel, high-voltage (HV) driver
is targeted for microoptomechanical systems. Each
device contains eight high-voltage amplifiers with an
output voltage range of 298 V to +160 V on the
condition that |V
HP
V
HN
|
300 V. Voltage gain is
set by external resistors. Each amplifier can output
up to 500
A, ideal for deflection and control of
optical MEMS mirrors. Output current limit is
programmed by an external resistor. Additionally,
careful attention is paid to minimizing offset drift over
temperature.
The LSP2908 requires one negative high-voltage
power supply (V
HN
) and one positive low-voltage
power supply (V
LP
). For positive output voltage appli-
cations, one positive high-voltage power supply
(V
HP
) is required. Corresponding to the eight chan-
nels are the eight inverting input pins, INx
(x = 1, 2, . . . , 8), and the corresponding eight output
pins, OUTPUTx (x = 1, 2, . . . , 8). Figure 1 is the
internal functional block diagram.
+IN is the noninverting input for all eight amplifiers.
All the amplifiers share the same noninverting input.
+IN should be connected to GND. The I
BIAS
pin will
set the current limit ((100 A to 500 A) 20%) for
the amplifiers by connecting it to an external resistor
R
ib
. The LSP2908 is available in a leaded surface-
mount 44-pin MQFP package.
1682.b(F)
Figure 1. LSP2908 Internal Block Diagram
IN8
+IN
OUTPUT 8
IN1
+
OUTPUT 1
+
LSP2908
2
2
Agere Systems Inc.
Advance Data Sheet
September 2001
8-Channel, High-Voltage Driver
LSP2908
Pin Information
Pin Diagram
2467(F)
Figure 2. LSP2908 Pin Diagram
Pin Descriptions
Table 1. Pin Descriptions
Pin Number
Pin Name
Function
Pin Total
Counts
Description
1, 2, 3, 10, 11, 13,
14, 15, 19, 20,
21, 23, 24, 31,
32, 33, 35, 36,
37, 40, 42, 43
NC
No Connect
22
Do not connect.
4, 5, 8, 9, 25, 26,
29, 30
INx
Analog Input
8
Inverting input for each channel.
6, 7, 12, 22, 27,
28, 34, 44
OUTPUTx
Analog Output
8
Output for each channel.
16
+IN
Analog Input
1
Noninverting input for all channels. Should be
grounded.
17
GND
Ground
1
Analog ground.
18
I
BIAS
Current Limit Control
1
Sets current limit with external resistor to GND.
38
V
HP
Power Supply
1
Positive high-voltage power supply.
39
V
LP
Power Supply
1
Positive low-voltage power supply.
41
V
HN
Power Supply
1
Negative high-voltage power supply.
V
HN
OUTPUT7
OUTPUT6
IN6
IN5
NC
NC
NC
OUTPUT2
OUTPUT3
IN3
NC
NC
1
3
4
5
6
7
8
9
10
11
2
44
42
41
40
39
38
37
36
35
34
43
12
14
15
16
17
18
19
20
21
22
13
33
31
30
29
28
27
26
25
24
23
32
IN7
NC
IN2
IN8
NC
NC
NC
NC
IN4
V
HP
V
LP
NC
NC
NC
NC
OU
T
P
U
T
8
NC
NC
OU
T
P
U
T
1
OU
T
P
U
T
5
NC
NC
+I
N
NC
NC
I
BI
AS
GN
D
NC
NC
OU
T
P
U
T
4
IN1
Agere Systems Inc.
3
Advance Data Sheet
September 2001
8-Channel, High-Voltage Driver
LSP2908
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are
absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in
excess of those given in the operational sections of the data sheet. Exposure to absolute maximum ratings for
extended periods can adversely affect device reliability.
Table 2. Absolute Maximum Ratings
Handling Precautions
Although protection circuitry has been designed for this device, proper precautions should be taken to avoid
exposure to electrostatic discharge (ESD) during handling and mounting. Agere Systems Inc. employs a human-
body model (HMB) and charged-device model (CDM) for ESD-susceptibility testing and protection design
evaluation. ESD voltage thresholds are dependent on the circuit parameters used in the defined model. No
industry-wide standard has been adopted for CDM. However, a standard HBM (resistance = 1500
, capacitance
= 100 pF) is widely used, and therefore, can be used for comparison purposes. The HBM ESD threshold (>500 V)
presented here was obtained by using these circuit parameters.
Application Considerations
Safe Handling of the High Voltage Device
LSP2908 is capable of operating with a negative power supply of up to 300 V or a positive power supply of up to
160 V. Due to the presence of high voltages, special care should be paid to safety issues.
Bypass Capacitors/Protection Series Resistor for the Power Supplies
To minimize noise coupling to the output, 0.1
F bypass capacitors should be placed as close as possible to all
power supply pins.
Parameter
Min
Typ
Max
Unit
Power Supply:
V
HN
V
HP
V
LP
V
HP
V
HN
0
V
LP
4.5
0
180.0
V
LP
12.0
195.0
300.0
160.0
20.0
300.0
V
V
V
V
Operating Temperature
40
25
85
C
Storage Temperature
65
25
150
C
Lead Temperature (soldering 10 seconds)
--
--
300
C
4
Agere Systems Inc.
Advance Data Sheet
September 2001
8-Channel, High-Voltage Driver
LSP2908
Handling Precautions
(continued)
Typical Application Circuit
In a typical application, the LSP2908 will directly drive the MEMS devices, as shown in Figure 3. One integrated
circuit replaces eight discrete amplifiers.
1683.b(F)
Figure 3. Typical Application Circuit
OUTPUT 1
OUTPUT 8
MEMS
+
+
MATRIX
475 k
475 k
LSP2908
DAC
IN1
IN 8
+IN
R
ib
10
0.1
F
10 M
10 M
GND
V
HN
V
HP
10
0.1
F
DAC
Agere Systems Inc.
5
Advance Data Sheet
September 2001
8-Channel, High-Voltage Driver
LSP2908
Electrical Characteristics
T
A
= 25 C, V
LP
= 12 V, V
HN
= 220 V, V
HP
= 12 V, noninverting input +IN = 0 V, R
I
= 475 k
, R
F
= 10 M
,
I
BIAS
resistor = 425 k
.
Table 3. Electrical Characteristics
Parameters
Symbol
Condition
Min
Typ
Max
Unit
Input Characteristics
Input Resistance
R
--
--
TBD
--
k
Input Offset Voltage
--
IN = 0 V
30
0
30
mV
Input Offset Voltage Drift
--
IN = 0 V
0 C--70 C
--
20
V/C
Input Bias Current
I(INx)
IN = 0 V
5
0
5
nA
Input Bias Current
I(+IN)
IN = 0 V
40
0
40
nA
Power Supply
Rejection Ratio
PSRR
V
HN
V
HP
V
LP
--
--
--
--
85
85
52
--
--
--
dB
Input Range
*
* V
LP
= 12 V, V
HN
= 150 V, and V
HP
= 150 V.
IN
--
5
--
10
V
Gain
Gain Temperature
Coefficient
G
TC
--
--
TBD
--
V/V/C
Amplifier Output Characteristics
Output Resistance
--
--
--
TBD
--
k
Amplifier Current Limit*
--
R
ib
= 425 k
80
100
120
A
Output Voltage
--
--
V
HN
+ 3.0 V
--
V
HP
3.0 V
V
Dynamics Characteristics
3 dB Bandwidth
C = 150 pF
R = 10 M
Controlled by R
ib
and V
LP
.
--
--
--
TBD
--
kHz
Slew Rate
C = 150 pF
R = 10 M
--
Input pulse = 0 V--5 V
R
F
= 10 M
R
I
= 392 k
--
--
0.62
0.47
--
--
V/s (rising)
V/s (falling)
Settling Time
,
C = 150 pF
R = 10 M
Settle to 5%.
--
Input pulse = 0 V--5 V
R
F
= 10 M
R
I
= 392 k
--
--
197
254
--
--
s (rising)
s (falling)
Power Supply Currents at Room Temperature
Quiescent Current
I(V
HN
)
V
HN
= 150.0 V
V
LP
= 12.0 V
V
HP
= 150.0 V
IN
= 0 V
400
500
600
A
I(V
HP
)
560
600
840
A
I(V
LP
)
184
230
276
A
Power Consumption
P
V
HN
= 150.0 V
V
LP
= 12.0 V
V
HP
= 150.0 V
IN
= 0 V
146
182.5
219
mW
6
Agere Systems Inc.
Advance Data Sheet
September 2001
8-Channel, High-Voltage Driver
LSP2908
Electrical Characteristics
(continued)
Output Current Range at Different Resistance on Pin I
BIAS
Figure 4 shows the output current range when different resistances are applied to pin I
BIAS
.
2533(F)
Figure 4. Resistor vs. Output Current Limit
350
300
250
200
150
100
50
0
500
400
300
200
100
CURRENT LIMIT ( A)
Ri
b
(
k
)
400
450
V
LP
= 12 V
V
LP
= 5 V
Agere Systems Inc.
7
Advance Data Sheet
September 2001
8-Channel, High-Voltage Driver
LSP2908
Package Diagram
5-2111(F)
44
1
10.00 0.20
13.20 0.20
10.00
0.20
13.20
0.20
PIN #1 IDENTIFIER ZONE
11
12
22
23
33
34
0.80 TYP
DETAIL A
2.35
MAX
0.10
SEATING
PLANE
1.95/2.10
DETAIL B
0.25 MAX
0.30/0.45
0.20
M
0.130/0.230
DETAIL B
0.25
0.73/1.03
1.60 REF
GAGE PLANE
SEATING PLANE
DETAIL A
Copyright 2001 Agere Systems Inc.
All Rights Reserved
September 2001
DS01-095ASP
Agere Systems Inc. reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed as a result of their use or application.
For additional information, contact your Agere Systems Account Manager or the following:
INTERNET:
http://www.agere.com
E-MAIL:
docmaster@agere.com
N. AMERICA: Agere Systems Inc., 555 Union Boulevard, Room 30L-15P-BA, Allentown, PA 18109-3286
1-800-372-2447, FAX 610-712-4106 (In CANADA: 1-800-553-2448, FAX 610-712-4106)
ASIA:
Agere Systems Hong Kong Ltd., Suites 3201 & 3210-12, 32/F, Tower 2, The Gateway, Harbour City, Kowloon
Tel. (852) 3129-2000, FAX (852) 3129-2020
CHINA: (86) 21-5047-1212 (Shanghai), (86) 10-6522-5566 (Beijing), (86) 755-695-7224 (Shenzhen)
JAPAN: (81) 3-5421-1600 (Tokyo), KOREA: (82) 2-767-1850 (Seoul), SINGAPORE: (65) 778-8833, TAIWAN: (886) 2-2725-5858 (Taipei)
EUROPE:
Tel. (44) 7000 624624, FAX (44) 1344 488 045
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