Texas Instruments TPS6021 Series, Руководство пользователя, Страница: 10 / 14

Schematic of the EVM
2-2
2.1 Schematic of the EVM
Figure 2–1 shows the schematic of the EVM. For this EVM, only ceramic ca-
pacitors with X5R or X7R material are used.
Figure 2–1. Schematic of the EVM
OUTPUT
3.3 V, 100 mA
INPUT
1.8 V to 3.6 V
C1
1
µ
F
C2
1
µ
F
C4
2.2
µ
F
C3
2.2
µ
F
R1
R2
1
2
3
4
5
6
7
8
9
10
R3
Low Battery
Warning
IN
C1–
C1+
LBI
TPS60210
OUT
C2–
C2+
LBO
GND
SNOOZE
100 nF
R4
Table 2–1. Bill of Material for the TPS60210 EVM
Component Value Part Number Manufacturer Description
C1, C2 1
µ
F, 10 V, 0805 LMK212BJ105KG–T Taiyo Yuden Flying capacitors
C3, C4 2.2
µ
F, 16 V, 1206 EMK316BJ225KL–T Taiyo Yuden Input and output capacitors
C5 100 nF Filter capacitor for the LBI
input signal
IC1 TPS60210 Texas Instruments
R1 402 k
Ω
E96-Series LBI input voltage adjustment
R2 576 k
Ω
E96-Series LBI input voltage adjustment
R3 1 M
Ω
Pullup for the open drain
output LBO
R4 1 M
Ω
Pullup for the SNOOZE input
Table 2–1 contains the bill of material of the TPS60210EVM-167. The follow-
ing paragraph describes the use of some of the parts.
R1 and R2 adjust the input voltage of the LBI input for low battery detection.
The resistive divider on the EVM is connected to V
I
. For the given resistor val-
ues, the LBO signal will go active (low) if V
I
is below 2.0 V. The divided input
voltage is compared to the internal reference voltage of 1.18 V. C5 works as
a filter capacitor for the LBI input voltage. This capacitor is recommended if line
or load transients occur. At the switching point of the LBI comparator, noise
may trigger the LBI, and this may lead to oscillations at the LBO pin. The LBO
output is an open-drain output and requires an external pullup resistor (R3).
For R3, a value between 100 k
Ω
and 1 M
Ω
is recommended. If your application
does not require low battery detection, these four parts can be omitted. In this
case, connect the LBI-pin to ground.