參數(shù)資料
型號: TPS601A-A
英文描述: PHOTOTRANSISTOR | NPN | 800NM PEAK WAVELENGTH | 50M | CAN-4.6
中文描述: 光電晶體管|叩| 800NM峰值波長|五十米|的CAN - 4.6
文件頁數(shù): 13/22頁
文件大?。?/td> 421K
代理商: TPS601A-A
TPS60100
REGULATED 3.3 V 200-mA LOW-NOISE
CHARGE PUMP DC/DC CONVERTER
SLVS213B – MAY 1999 – REVISED SEPTEMBER 1999
13
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
detailed description (continued)
start-up procedure
During start-up, i.e. when ENABLE is set from logic low to logic high, the switches T12 and T14 (charge pump
1), and the switches T22 and T24 (charge pump 2) are conducting to charge up the output capacitor until the
output voltage V
O
reaches 0.8
×
V
IN
. When the start-up comparator detects this limit, the IC begins to operate
in the mode selected with SKIP, COM and 3V8. This start-up charging of the output capacitor guarantees a short
start-up time and eliminates the need for a Schottky diode between IN and OUT.
pulse-skip mode
In pulse-skip mode (SKIP = high), the error amplifier disables switching of the power stages when it detects an
output higher than 3.3 V. The oscillator halts. The IC then skips switching cycles until the output voltage drops
below 3.3 V. Then the error amplifier reactivates the oscillator and switching of the power stages starts again.
The pulse-skip regulation mode minimizes operating current because it does not switch continuously and
deactivates all functions except bandgap reference and error amplifier when the output is higher than 3.3 V.
When switching is disabled from the error amplifier, the load is also isolated from the input. SKIP is a logic input
and should not remain floating. The typical operating circuit of the TPS60100 in pulse skip mode is shown in
Figure 1.
constant-frequency mode
When SKIP is low, the charge pump runs continuously at the frequency f
OSC
. The control circuit, fed from the
error amplifier, controls the charge on C
1F
and C
2F
by driving the gates of the FETs T
12
/T
13
and T
22
/T
23
,
respectively. When the output voltage falls, the gate drive increases, resulting in a larger voltage across C
1F
and C
2F
. This regulation scheme minimizes output ripple. Since the device switches continuously, the output
noise contains well-defined frequency components, and the circuit requires smaller external capacitors for a
given output ripple. However, constant-frequency mode, due to higher operating current, is less efficient at light
loads than pulse-skip mode.
IN
IN
C1+
C1–
ENABLE
PGND GND
OUT
OUT
FB
C2+
C2–
SYNC
SKIP COM 3V8
INPUT
1.8 V to 3.6 V
CIN
10
μ
F
OUTPUT
3.3 V 200 mA
CO = 22
μ
F
C2F
2.2
μ
F
C1F
2.2
μ
F
+
OFF/ON
TPS60100
+
Figure 30. Typical Operating Circuit TPS60100 in Constant Frequency Mode
Table 1. Tradeoffs Between Operating Modes
FEATURE
PULSE-SKIP MODE
(SKIP = High)
CONSTANT-FREQUENCY MODE
(SKIP = Low)
Best light-load efficiency
X
Smallest external component size for a given output ripple
X
Output ripple amplitude
Small amplitude
Very small amplitude
Output ripple frequency
Variable
Constant
Load regulation
NOTE: Even in pulse-skip mode the output ripple amplitude is small if the push-pull operating mode is selected via COM.
Very good
Good
Powered by ICminer.com Electronic-Library Service CopyRight 2003
相關PDF資料
PDF描述
TPS601A-B PHOTOTRANSISTOR | NPN | 800NM PEAK WAVELENGTH | 50M | CAN-4.6
TPS601A-C PHOTOTRANSISTOR | NPN | 800NM PEAK WAVELENGTH | 50M | CAN-4.6
TPS60200DGSR Analog IC
TPS60201DGSR Analog IC
TPS60202DGSR Analog IC
相關代理商/技術參數(shù)
參數(shù)描述
TPS601A-A(F) 制造商:Toshiba 功能描述:Cut Tape
TPS601A-B 制造商:未知廠家 制造商全稱:未知廠家 功能描述:PHOTOTRANSISTOR | NPN | 800NM PEAK WAVELENGTH | 50M | CAN-4.6
TPS601AB(F) 制造商:Toshiba 功能描述:Cut Tape
TPS601A-C 制造商:未知廠家 制造商全稱:未知廠家 功能描述:PHOTOTRANSISTOR | NPN | 800NM PEAK WAVELENGTH | 50M | CAN-4.6
TPS601A-C(F) 制造商:Toshiba 功能描述:Cut Tape