Datenblatt-pdf.com


TC1043 Schematic ( PDF Datasheet ) - Microchip Technology

Teilenummer TC1043
Beschreibung Low Power Voltage Reference
Hersteller Microchip Technology
Logo Microchip Technology Logo 




Gesamt 20 Seiten
TC1043 Datasheet, Funktion
TC1043
Linear Building Block Low Power Voltage Reference with
Dual Op Amp, Dual Comparator, and Shutdown Mode
Features
• Combines Two Op Amps, Two Comparators and
a Voltage Reference in a Single Package
• Optimized for Single-Supply Operation
• Small Package: 16-Pin QSOP
• Ultra Low Input Bias Current: Less than 100pA
• Low Quiescent Current: Operating 16µA (Typ.)
Shutdown 6µA (Typ.)
• Rail-to-Rail Inputs and Outputs
• Operates Down to VDD = 1.8V
• Reference and One Comparator Remain Active in
Shutdown to Provide Supervisory Functions
Applications
• Power Management Circuits
• Battery Operated Equipment
• Consumer Products
• Replacements for Discrete Components
Device Selection Table
Part Number
TC1043CEQR
Package
16-Pin QSOP
Temperature
Range
-40°C to +85°C
Package Type
16-Pin QSOP
A1IN+ 1
A1IN– 2
A2IN+ 3
A2IN– 4
C1OUT 5
C2OUT 6
SHDN 7
VSS 8
16 VDD
15 A1OUT
14 A2OUT
13 C1IN+
12 C1IN–
11 C2IN+
10 C2IN–
9 VREF
General Description
The TC1043 is a mixed-function device combining two
general purpose op amps, two general purpose com-
parators, and a voltage reference in a single 16-Pin
package.
This increased integration allows the user to replace
two or three packages, saving space, lowering supply
current, and increasing system performance. A shut-
down input, SHDN, disables the op amps and one of
the comparators, placing their outputs in a high-imped-
ance state. The reference and one comparator stay
active in shutdown mode. Standby power consumption
is typically 6µA. Both the op amps and comparators
have rail-to-rail inputs and outputs which allows opera-
tion from low supply voltages with large input and out-
put signal swings.
Packaged in a 16-Pin QSOP, the TC1043 is ideal for
applications requiring high integration, small size and
low power.
© 2002 Microchip Technology Inc.
DS21347B-page 1






TC1043 Datasheet, Funktion
TC1043
4.0 TYPICAL APPLICATIONS
The TC1043 lends itself to a wide variety of applica-
tions, particularly in battery powered systems. It typi-
cally finds application in power management,
processor supervisory, and interface circuitry.
4.1 Wake-Up Timer
Many microcontrollers have a low power “sleep” mode
that significantly reduces their supply current. Typically,
the microcontroller is placed in this mode via a software
instruction, and returns to a fully enabled state upon
reception of an external signal (“wake-up”). The wake-
up signal is usually supplied by a hardware timer. Most
system applications demand that this timer have a long
duration (typically seconds or minutes), and consume
as little supply current as possible.
The circuit shown in Figure 4-1 is a wake-up timer
made from comparator CMPTR2. (CMPTR2 is used
because the wake-up timer must operate when SHDN
is active.) Capacitor C1 charges through R1 until a volt-
age equal to VR is reached, at which point the WAKE-
UP is driven active. Upon wake-up, the microcontroller
resets the timer by forcing a logic low on a dedicated,
open drain I/O port pin. This discharges C1 through R4
(the value of R4 is chosen to limit the maximum current
sunk by the I/O port pin). With a 3V supply, the circuit
as shown consumes typically 6µA and furnishes a
nominal timer duration of 25 seconds.
4.2 Precision Battery Monitor
Figure 4-2 is a precision battery low/battery dead mon-
itoring circuit. Typically, the battery low output warns
the user that a battery dead condition is imminent. Bat-
tery dead typically initiates a forced shutdown to pre-
vent operation at low internal supply voltages (which
can cause unstable system operation).
The circuit of Figure 4-2 uses a single TC1043 (one op
amp is unused) and only six external resistors. AMP 1
is a simple buffer, while CMPTR1 and CMPTR2 provide
precision voltage detection using VR as a reference.
Resistors R2 and R4 set the detection threshold for
BATTLOW, while resistors R1 and R3 set the detection
threshold for BATTFAIL. The component values shown
assert BATTLOW at 2.2V (typical) and BATTFAIL at
2.0V (typical). Total current consumed by this circuit is
typically 22µA at 3V. Resistors R5 and R6 provide hys-
teresis for comparators CMPTR1 and CMPTR2
respectively.
4.3 Dual LDO with Shutdown
Figure 4-3 shows a portion of a TC1043 configured as
a dual low dropout regulator with shutdown. AMP1 and
AMP2 are independent error amplifiers that use VR as
a reference. Resistors RA1, RB1, RA2 and RB2 set the
feedback around the amplifiers and therefore deter-
mine the output voltage settings (please see equation
in the figure). RA1, RB1, RA2 and RB2 can have large
ohmic values (i.e. 100’s of k) to minimize supply cur-
rent.
Using the 2N2222 output transistors as shown, these
regulators exhibit low dropout operation. For example,
with VOUT = 3.0V, the typical dropout voltage is only
50mV at an output current of 50mA. The unused com-
parators can be used in conjunction with this circuit as
power-on reset or low voltage detectors for a complete
LDO solution at a very low installed cost.
4.4 External Hysteresis
Hysteresis can be set externally with two resistors
using positive feedback techniques (see Figure 4-3).
The design procedure for setting external comparator
hysteresis is as follows:
1. Choose the feedback resistor RC. Since the
input bias current of the comparator is at most
100pA, the current through RC can be set to
100nA (i.e. 1000 times the input bias current)
and retain excellent accuracy. The current
through RC at the comparator’s trip point is VR /
RC where VR is a stable reference voltage.
FIGURE 4-1:
WAKE-UP TIMER
C1
10µF
R1
5M
R4
VDD
VDD
Microcontroller
I/O*
CMPTR2
+
WAKE-UP
VR
TC1043
*Open Drain Port Pin
2. Determine the hysteresis voltage (VHY) between
the upper and lower thresholds.
3. Calculate RA as follows:
DS21347B-page 6
© 2002 Microchip Technology Inc.

6 Page









TC1043 pdf, datenblatt
TC1043
FIGURE 4-10:
SECOND ORDER SAT BANDPASS FILTER
Gain = 0 dB
Q = 30
Q = FC
BW (3 dB)
FC = 6kHz
TC1043
.036 µF
48.7k
VIN
24.3k
.036 µF
11.2
VDD
+
VDD/2
VDD/2
TC1043 Op Amp
VOUT
DS21347B-page 12
© 2002 Microchip Technology Inc.

12 Page





SeitenGesamt 20 Seiten
PDF Download[ TC1043 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
TC1040Dual Low Power Comparator and Voltage ReferenceMicrochip Technology
Microchip Technology
TC1041Dual Low Power Comparator and Voltage ReferenceMicrochip Technology
Microchip Technology
TC1043Low Power Voltage ReferenceMicrochip Technology
Microchip Technology
TC1044SCharge Pump DC-TO-DC Voltage ConverterMicrochip Technology
Microchip Technology
TC1044SCHARGE PUMP DC-TO-DC VOLTAGE CONVERTERTelCom Semiconductor
TelCom Semiconductor

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche