XTAL (Crystal Oscillator) Calculation
Load Capacitor Calculation
C1 = C2 = 2 × (CL + CS)
pF
pF
-
pF
NTC (Negative Temperature Coefficient) Calculation
1. R1 - Target Resistance
Parameters:
- R0 - Calibration resistance
- T - Absolute temperature: 273.15 K
- T0 - Calibration temperature (target): 25°C
- B - Thermistor Beta
- T1 - Target Temperature
- R1 - Target Resistance
R1 = R0 × exp(B × (1/T1 - 1/T0))
Ω
K
%
°C
Calculation Steps:
298.15
K
-
K
-
R1 Results:
-
Ω
-
Ω
-
Ω
2. T1 - Target temperature
Parameters:
- R0 - Calibration resistance
- T - Absolute temperature: 273.15 K
- T0 - Calibration temperature (target): 25°C
- B - Thermistor Beta
- T1 - Target Temperature
- R1 - Target Resistance
T1 = 1 / (ln(R1/R0) / B + 1/T0)
Ω
K
%
Ω
Calculation Steps:
298.15
K
-
K
T1 Results:
-
°C
-
°C
-
°C
LED (Light Emitting Diode) Calculation
LED Resistance Calculation
R = (VBAT - VF) / ILED
V
V
V
V
mA
mA
mA
-
kΩ
-
kΩ
-
kΩ
FET (Field Effect Transistor) Calculation
MOSFET impact on charger headroom
RDS_ON_MAX = (VD - (VFLOAT + VHEADROOM)) / (ILOAD + IFAST)
Parameters:
- VD - Drain voltage of the MOSFET
- VFLOAT - Configurable charging float voltage
- VHEADROOM - Minimum headroom voltage required by the charger
- ILOAD - Peak system load
- IFAST - Maximum charging current, referred to as fast charging current
- RDS_ON_MAX - Maximum on-resistance
V
V
V
A
A
-
Ω
PCB Calculation
1. Trace length
Max allowed difference in trace length between a clock and belonging digital high speed signals.
MHz
%
-
ps
-
ps/mm
-
-
mm
-
mm
2. Trace resistance
mm
mm
mm
mm
-
Ω·m
-
1/°C
°C
°C
-
Ω
mA
-
V
3. Trace current
Imax = k × (ΔT)0.44 × (A)0.725
mm
mm
°C
-
A
4. Via current
Imax = 0.093 × (ΔT)0.44 × (A)0.75
mm
mm
μm
°C
Note:
The constant 0.093 is more commonly used for via calculations and typically yields ~3.9× higher current capacity than 0.024.
The 0.024 constant is more conservative and matches the IPC-2152 internal trace constant.
Choose based on your design requirements and thermal management capabilities.
The constant 0.093 is more commonly used for via calculations and typically yields ~3.9× higher current capacity than 0.024.
The 0.024 constant is more conservative and matches the IPC-2152 internal trace constant.
Choose based on your design requirements and thermal management capabilities.
A
Unit Converter
1. mil ↔ mm
↔
Latest calculations (5s delay):
-
-
-
Pre-defined Values:
1 mil ↔ 0.0254 mm
2 mil ↔ 0.0508 mm
3 mil ↔ 0.0762 mm
4 mil ↔ 0.1016 mm
5 mil ↔ 0.1270 mm
6 mil ↔ 0.1524 mm
7 mil ↔ 0.1778 mm
8 mil ↔ 0.2032 mm
9 mil ↔ 0.2286 mm
10 mil ↔ 0.2540 mm
11 mil ↔ 0.2794 mm
12 mil ↔ 0.3048 mm
13 mil ↔ 0.3302 mm
14 mil ↔ 0.3556 mm
15 mil ↔ 0.3810 mm
2. mC ↔ mA
=
-