UC1834
UC2834
UC3834 High Efficiency Linear Regulator
FEATURES
•Minimum V IN - V OUT Less Than
0.5V At 5A Load With External
Pass Device
•Equally Usable For Either Positive
or Negative Regulator Design
•Adjustable Low Threshold Current英语演讲比赛
Sen Amplifier
•Under And Over-Voltage Fault Alert
With Programmable Delay
•Over-Voltage Fault Latch With
100mA Crowbar Drive Output
DESCRIPTION
The UC1834 family of integrated circuits is optimized for the design of low
input-output differential linear regulators. A high gain amplifier and 200mA
sink or source drive outputs facilitate high output current designs which u
an external pass device. With both positive and negative precision refer-
ences, either polarity of regulator can be implemented. A current n am-
plifier with a low, adjustable, threshold can be ud to n and limit
currents in either the positive or negative supply lines.
In addition, this ries of parts has a fault monitoring circuit which ns我要当学霸
both under and over-voltage fault conditions. After a ur defined delay for
transient rejection, this circuitry provides a fault alert output for either fault
condition. In the over-voltage ca, a 100mA crowbar output is activated.新生儿会便秘吗
An over-voltage latch will maintain the crowbar output and can be ud to
shutdown the driver outputs. System control to the device can be accom-
modated at a single input which will act as both a supply ret and remote
shutdown terminal. The die are protected against excessive power dissi-
pation by an internal thermal shutdown function.
玉米种植时间6/94
ABSOLUTE MAXIMUM RATINGS (Note 1)
Input Supply Voltage, V IN +. . . . . . . . . . . . . . . . . . . . . . . . . 40V Driver Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400mA Driver Source to Sink Voltage. . . . . . . . . . . . . . . . . . . . . . . 40V Crowbar Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −200mA +1.5V Reference Output Current. . . . . . . . . . . . . . . . . . −10mA Fault Alert Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V Fault Alert Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15mA Error Amplifier Inputs. . . . . . . . . . . . . . . . . . . . . . −0.5V to 35V Current Sen Inputs. . . . . . . . . . . . . . . . . . . . . . −0.5V to 40V O.V. Latch Output Voltage. . . . . . . . . . . . . . . . . . −0.5V to 40V O.V. Latch Output Current. . . . . . . . . . . . . . . . . . . . . . . . 15mA Power Dissipation at T A = 25°C. . . . . . . . . . . . . . . . . . 1000mW Power Dissipation at T C = 25°C. . . . . . . . . . . . . . . . . . 2000mW Operating Junction Temperature. . . . . . . . . . −55°C to +150°C Storage Temperature. . . . . . . . . . . . . . . . . . . −65°C to +150°C Lead Temperature (soldering, 10 conds). . . . . . . . . . . 300°C Note 1:Voltages are reference to V IN−, Pin 5.
Currents are positive into, negative out of the specified
terminals.
落实措施Consult Packaging ction of Databook for thermal
limitations and considerations of package.
ELECTRICAL CHARACTERISTICS:Unless otherwi stated, the specifications apply for T A=−55°C to +125°C
for the UC1834, −40°C to +85°C for the UC2834, and 0°C to +70°C for the
Pin 2. The −2.0V output will change −2.3mV per µA of imbalance.
Note 3:Thermal shutdown turns off the driver. If Pin 15 (O.V. Latch Output) is tied to Pin 14 (Compensation/Shutdown) the O.V. Latch will be ret.
ELECTRICAL CHARACTERISTICS:Unless otherwi stated, the specifications apply for T A =−55°C to +125°C
for the UC1834, −40°C to +85°C for the UC2834, and 0°C to +70°C for the UC3834. V IN+ = 15V, V IN − = 0V. T A = T J
UC3834 Both the current n and error amplifiers on the UC1834
are transconductance type amplifiers. As a result, their volt-溜溜球图片
age gain is a direct function of the load impedance at their
shared output pin, Pin 14. Their small signal voltage gain as
a function of load and frequency is nominally given by;
A V E⁄A=Z L(f)
700Ω
and A V C. S.⁄A=
Z L(f)
70Ω
安全对联for: f ≤ 500kHz and |Z L(f)| ≤ 1 MΩ
Where:
A V=Small Signal Voltage Gain to pin 14.
Z L(f) = Load Impedance at Pin 14.
昆明美食推荐The UC1834 fault delay circuitry prevents the fault outputs from responding to transient fault conditions. The delay ret latch insures that the full, ur defined, delay pass before an over-voltage fault respon occurs. This prevents unnecessary crowbar, or latched-off conditions, from occurring following sharp under-voltage to over-voltage transients.The crowbar output on the UC1834 is activated following a sustained over-voltage condition. The crowbar output remains high as long as the fault condition persists, or, as long as the over-voltage latch is t. The latch is t with an over-voltage fault if the voltage at Pin 15 is above the latch ret threshold, typically 0.4V. When the latch is t, its Q− output will pull Pin 15 low through a ries diode. As long as a nominal pull-up load exists, the ries diode prevents Q− from pulling Pin 15 below the ret threshold. However, Pin 15 is pulled low enough to disable the driver outputs if Pins 15 and 14 are tied together. With Pin 15 and 14 common, the regulator will latch off in respon to an over-voltage fault. If the fault condition is cleared and Pins 14 and 15 are momen-tarily pulled below the latch ret threshold, the driver out-puts are re-enabled.
UC3834
UNITRODE CORPORATION
7 CONTINENTAL BL VD. • MERRIMACK, NH 03054
TEL. (603) 424-2410 • FAX (603) 424-3460
