TCM828ECT713 Microchip Technology, TCM828ECT713 Datasheet - Page 4

• Manufacturer Part Number: TCM828ECT713
• Description: IC CHARGE PUMP CONV SOT23A-5
• Manufacturer: Microchip Technology
• Type: Switched Capacitor (Charge Pump), Doubler, Invertingr

Specifications of TCM828ECT713

• Package / Case: SOT-23-5, SC-74A, SOT-25
• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: -1.5 ~ -5.5 V, ±3 ~ ±11 V
• Current - Output: 25mA
• Frequency - Switching: 12kHz
• Voltage - Input: 1.5 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Power - Output: 240mW
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Function: Inverting, Step Up
• Output Voltage: - 1.5 V to - 5.5 V, 3 V to 11 V
• Output Current: 25 mA
• Maximum Operating Temperature: 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 158-2031-2; 158-2031-2; TCM828ECT713TR

TCM828/829-4
Capacitor Selection
output ripple voltage, it is recommended that low ESR
capacitors be used. Additionally, larger values of C1 will
lower the output resistance and larger values of C2 will
reduce output ripple. (See Equation 1(b)).
ing output resistance values @ +25 C. It assumes a 0.1
ESR
for various values of C2. The V
output load current and 0.1
Table 1. Output Resistance vs. C1 (ESR = 0.1 )
Table 2. Output Voltage Ripple vs. C2 (ESR = 0.1 ) I
Input Supply Bypassing
AC impedance and minimize noise effects due to the switch-
ing internal to the device. The recommended capacitor
depends on the configuration of the TCM828/829.
mended that a large value capacitor (at least equal to C1) be
connected from the input to GND. If the device is loaded
from IN to OUT a small (0.1 F) capacitor from IN to OUT is
sufficient.
Voltage Inverter
is the inverter (Figure 3). This application uses two external
capacitors – C1 and C2 (plus a power supply bypass
capacitor, if necessary). The output is equal to V –
voltage drops due to loading. Refer to Table 1 and Table 2
for capacitor selection.
TCM828
TCM829
C1( F)
C2( F)
In order to maintain the lowest output resistance and
Table 1 shows various values of C1 and the correspond-
The V
If the device is loaded from OUT to GND it is recom-
The most common application for charge pump devices
100
100
C1
0.1
3.3
3.3
10
47
10
47
1
1
and 2 R
5/22/00
IN
input should be capacitively bypassed to reduce
TCM828 V
SW
TCM828 R
. Table 2 shows the output voltage ripple
835
254
85
20
10
RIPPLE
850
100
42
25
18
17
OUT
ESR
RIPPLE
(mV)
( )
C2
.
values assume 10mA
TCM829 V
TCM829 R
302
286
RIPPLE
IN
45
25
19
17
17
88
31
8
5
OUT
plus any
OUT
10mA
(mV)
( )
4
Cascading Devices
increase output voltage (Figure 4). If the output is lightly
loaded, it will be close to (– 2 x V
R
can be seen that the output resistance rises rapidly for
multiple cascaded devices. For large negative voltage
requirements see the TC682 or TCM680 data sheets.
Paralleling Devices
can be connected in parallel (Figure 5). The output resis-
tance will be reduced by a factor of N where N is the number
of TCM828/829’s. Each device will require it’s own pump
capacitor (C1), but all devices may share one reservoir
capacitor (C2). However, to preserve ripple performance the
value of C2 should be scaled according to the number of
paralleled TCM828/829’s.
C1
*10 F (TCM828)
OUT
Figure 4. Cascading TCM828s or TCM829s to Increase Output Voltage
Two or more TCM828/829’s can be cascaded to
To reduce the value of R
of the first device multiplied by the I
3
4
5
TCM828
TCM829
3
1
2
"1"
IN
OUT
C1 –
Voltage Inverter
TCM828
TCM829
Figure 3. Test Circuit
2
1
C1
GND
C1 +
V
3.3 F*
+
IN
C3
Switched Capacitor
Voltage Converters
© 2001 Microchip Technology Inc.
. . .
. . .
OUT
4
5
C2
3.3 F*
IN
C1
) but will droop at least by
3
4
, multiple TCM828/829s
5
V
OUT = –n
TCM828
TCM829
"n"
Q
3.3 F*
of the second. It
C2
V
V
IN
R
IN
L
2
1
C2
DS21488A
V
V
OUT
OUT