Linear Technology 453' LT1970 Quick Start Manual

DESCRIPTION
Demonstration circuit 453 is usef ul f or evaluating the
LT1970, a pow er amplif ier w ith adj ustable current limit-
ing. The demo circuit is available in tw o versions;
DC453A-A w ith up to 500mA of output current and
DC453A-B f or applications w ith up to 5 Amps of output
current. For the 5 Amp version a Class B M O SFET based
current boost stage has been added to the output section
w ith current limit control still provided by the LT1970.
The maximum output current of the board is set by tw o
on-board potentiometers to permit independent control
of the sinking and sourcing current limit. The current
limit adj ustment can also be provided by external voltage
sources. Symmetrical sourcing and sinking current limit
w ith a single control is also possible.
TYPICAL PERFORMANCE SUMMARY
T = 25°C, Com m on ±12V Suppl i es
A
SYM BOL PARAM ETER
V Pow er Supply Range
SUPPLY
I Adj ustable Output Current Limit Range
OUT
BW Small Signal –3dB Bandw idth
S
BW Large Signal –3dB Bandw idth
L
SR Slew Rate
V Output Sat Voltage High
SATH
Adjustable Current Limiting
LEDs provide an indication of f aults detected by the
LT1970. Separate indicators illuminate w hen the amplif ier
enters sourcing or sinking current limit and if the LT1970
overheats and enters thermal shutdow n protection.
Several j umpers enable f lexible amplif ier operation. Con-
f igurations include:
Single or dual pow er supplies
I
Separate or common input stage and pow er output
I
stage supplies
AC or DC coupled inputs
I
N on-Inverting gains of 1 or 2, Inverting gain of –1
I
Separate or common current limit control
I
Design files for this circuit board are available. Call
the LTC factory.
, LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT and
Pow erPath are trademarks of Linear Technology Corporation.
CONDI TI ONS
Single Supply
Dual Supply
DC453A-A (LT1970 basic amplif ier), Vcc ≥ 8V
DC453A-B (Boosted)
DC453A-A (LT1970 basic amplif ier)
A = +1, Vout=200mV , R =100Ω,
V P-P LOAD
DC453A-B (Boosted)
A = +1, Vout=200mV , R =10Ω
V P-P LOAD
DC453A-A (LT1970 basic amplif ier)
A = +1, Vout=20V , R =100Ω
V P-P LOAD
DC453A-B (Boosted)
A = +1, Vout=10V , R =10Ω,
V P-P LOAD
DC453A-A (LT1970 basic amplif ier), V
Common ±12V Supplies, R =250Ω
LOAD
Common ±12V Supplies, R =25Ω
LOAD
Vcc/ Vee=±12V and V+/ V-=±5V, R
LOAD
Vcc/ Vee=±12V and V+/ V-=±5V, R
LOAD
DC453A-B (Boosted), See Operational Notes
DEMO CIRCUIT 453
QUICK START GUIDE
Power Amplifier with
M I N TYP
8
±8
±4
±0.04
1.6
7.2
58
7
1.6
=V+-V
SAT OUT
1.4
2.1
=100Ω 0.1
=10Ω 0.8
LT1970
LT1970
M AX UNI TS
36 V
±18 V
±500 mA
±5 A
M Hz
KHz
KHz
KHz
V/ µS
V
V
V
V
1