32-bit ARM Cortex™-M3 MCU
HT32F1251/51B/52/53
Internal Clock Characteristics
Table 10. High Speed Internal Clock (HSI) Characteristics
TA = 25°C, unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
High Speed Internal
Oscillator Frequency (HSI ) TA = -40°C ~ +85°C
VDD33 = 3.3 V,
fHSI
TBD
8
TBD
MHz
HSI Oscillator Frequency
accuracy
Factory-trimmed,
VDD33 = 3.3 V, TA = 25°C
ACCHSI
DHSI
-1
35
—
—
—
+1
65
—
%
%
HSI Oscillator Duty cycle
VDD33 = 3.3 V, fHSI = 8 MHz
HSI Oscillator Operating
Current
IDDHSI
V
DD33 = 3.3 V, fHSI = 8 MHz
0.92
mA
VDD33 = 3.3 V,
HSI = 8 MHz, HSIRCBL = 0 (HSI
Ready Counter Bits Length 7 Bits )
tSUHSI
HSI Oscillator Startup time
f
—
17
—
μs
NOTE: HSIRCBL field is in PWRCU HSIRCR register
Table 11. Low Speed Internal Clock (LSI) Characteristics
TA = 25°C, unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
Low Speed Internal Oscillator VDD33 = VBAT = 3.3 V,
fLSI
25
32
43
kHz
Frequency(LSI)
TA = -40°C ~ +85°C
LSI Oscillator Operating
Current
VDD33 = VBAT = 3.3 V,
TA = 25°C
IDDLSI
tSULSI
—
—
1.0
35
2
μA
VDD33 = VBAT = 3.3 V,
TA = 25°C
LSI Oscillator Startup time
—
ms
Rev. 1.00
25 of 35
May 27, 2011
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
